Workstation Notes
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Directions to Wallops from Refuge Inn
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High Voltage Multimeter: -! Correct connection
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High Voltage Multimeter: -! Continuity Checks
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High Voltage Multimeter: -! Low Voltage check
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High Voltage Multimeter: -! High Voltage check
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Grounding and ESD: -! Put on an ESD Wrist Strap to remain grounded. - Wrist strap must make contact with your wrist/arm or it doesn’t ground you. - Will protect any parts from electrostatic discharge (ESD) and its harmful effects. - Wear them always - All helpers must be wearing one that is attached to your mat before touching your hardware
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Soldering Station: -! Turn on the soldering iron -! Set the temperature control on the soldering iron to a temperature less than 700 °F and greater than 450 °F. - As a general rule use a temperature in the range between 550 and 650 degrees Fahrenheit.
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Soldering Station
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Tinning the iron -! Tin the tip of the soldering iron by melting an inch or so of solder on the tip. -! The iron will now look shiny on the tip. -! Then wipe any excess solder on the golden sponge. -! Now place the iron back into the holder. Tinning your soldering iron in this manner will aid in future soldering. 11 RockOn! 2015 RockOn 2015 Workshop
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Prep Step 4: Tinning the iron (close-up)
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TIPS: -! Use caution when clipping leads to avoid flinging metal across the room.
workmanship. nasa.gov
-! All soldering must achieve a good solder fillet on the pad as shown for circuit reliability. Example of a good solder fillet -! Also clip the leads as shown in the solder fillet example with little excess wire above the top of the fillet.
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TIPS:
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TIPS: - How much solder? - Cold Solder Joints (CSJs)
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TIPS: Other Soldering Tips: -! Easy to add solder or re-melt vs. remove it -! Easier to solder using the side of the iron, rather than the tip -! Make sure the iron is heating both the pad and the pin
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TIPS: Pre-Bending 101: -! Pre-bending is a technique that allows components to be easily inserted into a PCB. -! Pre-bending also allows components to lay more flush with the board. -! Bending components to the correct bend radius takes practice, but mastering the technique will reap rewarding benefits!
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Pre-Bending: Pre-Bending 101: -! Start with the bending and prodding tool in the position shown in the top picture.
90°
-! Choose a location along the length of the tool that will yield the appropriate bend radius. -! Use your thumb to bend the lead such that the component and lead are orthogonal. 18 RockOn! 2015
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TIPS: Other Soldering Tips: - Good lighting and eye protection
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Geiger Counter
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What Are We Building ? - Basic Geiger Counter - Audio and Visual Cues for Radiation Detection - Can detect Alpha, Beta, and Gamma Radiation http://youtu.be/gNgHl2FkswE http://youtu.be/bcjMOr-qiwA 21 RockOn! 2015 RockOn 2015 Workshop
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What Are We Building ? - Board may seem like an array of confusing electronics but is actually fairly organized - Will build this board by subsystems to help explain the organization
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Integral Systems:
-!Geiger Tube -!MC14049CP Hex Inverter -!LN555C 555 Timer -!Mini Step-up Transformer -!GS 7805 5V Voltage Regulator -!IRF830 Power MOSFET 23 RockOn! 2015
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Verifying Kit Contents
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Save the Earth from RockOn Plastic Bags -! All our kits are very organized by putting all the parts for each step into a plastic bag - Concept works great but…
GM TUBE 26 RockOn! 2015 RockOn 2015 Workshop
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Save the Earth from RockOn Plastic Bags - So this year, please keep all your bags - Please turn them in at the end of the workshop - Prizes for the best organized recycling of bags
GM TUBE 27 RockOn! 2015 RockOn 2015 Workshop
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Verify Kit Contents -! Complete Bill of Materials (BOM)
GM TUBE 28 RockOn! 2015 RockOn 2015 Workshop
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Verify Kit Contents -! Open your kits and verify the contents with the provided list and visual layout -! You won’t need the GM Tube until the last few steps -! We will hand these items out when we reach the final steps
GM TUBE 29 RockOn! 2015 RockOn 2015 Workshop
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Reading a Resistor: The resistors in this workshop have already been organized by value. In the event that your resistors get mixed, please refer to the chart at the left to classify your resistors, or use your multimeter If you are unsure, don’t hesitate to raise your hand and ask for assistance.
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Verify Kit Contents: Resistors -!R1 = 4.3 K! = (Yellow Orange Red) -!R2 = 15 K! = (Brown Green Orange) -!R3 = 5.6 K! = (Green Blue Red) -!R4 = 680 K! = (Blue Gray Yellow) -!R5 = 10 M! = (Brown Black Blue) 31 RockOn! 2015 RockOn 2015 Workshop
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Verify Kit Contents: Resistors -!R7 = 150 K! = (Brown Green Yellow) -!R8 = 470 ! = (Yellow Violet Brown) -!R9 = 330 ! = (Orange Orange Brown)
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Verify Kit Contents: Capacitors -! Some capacitors have polarity, while others do not -! Majority of capacitors used are not polarized -! *Note C2=C7=C8, C4=C5, and C3=C9 -! Some capacitors in use can carry charge long after power has been disconnected from the circuit (10-20 seconds) -! Use caution especially around the high voltage (HV) section of the circuit to avoid a discharge shock -! The capacitors near the HV section have the capability of holding a 1 KV burst and will SHOCK YOU if touched with power connected or shortly after power is disconnected! 33 RockOn! 2015 RockOn 2015 Workshop
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Verify Kit Contents: Capacitors -! C1 = Blue Ceramic 0.0047 µF @ 100V -! C2 = Yellow Ceramic 0.01 µF @ 50V -! C3(±) = Black Electrolytic 220 µF @ 16V -! C4 = Orange Ceramic 0.01 µF @ 1KV -! C5 = Orange Ceramic 0.01 µF @ 1KV
C1
C2
Some components will look different
+
C3
C4
C5
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Verify Kit Contents: Capacitors -! C6 = Orange Ceramic 0.01 uF @100V -! C7 = Yellow Ceramic or Orange Ceramic 0.01 µF @ 50V -! C8 = Yellow Ceramic 0.01 µF @ 50V
Some components -! C9(±) = Black Electrolytic 220 µF @ 16V will look different
C6
C7
C8
C9 35 RockOn! 2015
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Verify Kit Contents: Diodes -! All diodes in this kit have polarity -! *Note these similar diodes D1=D10, D5=D6 , D2=D3=D9 -! D1 = 1N914 = -! D2 = 1N4007 @ 1KV = -! D3 = 1N4007 @ 1KV =
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Verify Kit Contents: Diodes -! D4 = 1N5271 @ 100V = -! D5 = 1N5281 @ 200V = -! D6 = 1N5281 @ 200V = -! D9 = 1N4007 @ 1KV =
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Verify Kit Contents: Diodes -! D8 = 1N75 @ 5.1 V =
-! D10 = 1N914=
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Verify Kit Contents: Miscellaneous Q1 (7805 Regulator)
Q2 (Power FET)
Q3 (NPN Transistor)
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Verify Kit Contents: Miscellaneous -! D7 (Red Led)
-!T1 (Mini Step-up Transformer)
+ -
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Verify Kit Contents: Miscellaneous -! U1 (16 pin 4049 chip and socket)
-! U2 (8 pin 555 Timer chip and socket) 41 RockOn! 2015 RockOn 2015 Workshop
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Verify Kit Contents: Miscellaneous
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Verify Kit Contents: Miscellaneous
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Board Schematic:
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Board Schematic:
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Schematic Overview – Part Highlighting: Parts to be added
-! Blue highlights indicate parts will be added to the board in the current step.
Parts added previously
-! Green highlights indicate components already on the board but relevant to the current step. 46 RockOn! 2015 RockOn 2015 Workshop
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Schematic Overview – Coordinates (A1): Numbers across top
Letters along side
-! All schematic close-ups include coordinates so they can be easily located in your schematic printout. -! The coordinates correspond to the letters across the side of the schematic and the numbers across the top. 47 RockOn! 2015
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Let’s Start Building!
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RBF/G-Switch Headers:
RBF Pin
G-Switch
-! Solder two (2) of the 2X1 headers into the footprints labeled RBF Pin and G-Switch. -! As always, ensure they are flush with the board. 49 SHOT 1 2015 RockOn 2015 Workshop
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Working Ahead: - We are a car with 24 cylinders
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Working Ahead: - We are a car with 12 cylinders
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Current Sub System: Geiger Counter Sub Systems: DC Voltage Regulation Oscillator High Voltage (Unregulated) High Voltage Regulation Output Pulse 52 RockOn! 2009 RockOn 2015 Workshop
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TIPS: - The ESD wrist strap must be tight on your wrist at all times -! DO NOT linger on parts with the soldering iron -! As a general rule use a 3-5 second linger time with a 10-20 second cool time for parts -! Mount and solder components flush to the board unless otherwise stated 53 RockOn! 2015 RockOn 2015 Workshop
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DC Voltage Regulation– Coordinates (C1): 5.0V
Rectifying Diode
ator
g Volta
gul e Re
-! Creates a regulated 5.0V power voltage that is reverse bias protected from a diode. -! 5.0 Volt signal is created with a linear voltage regulator that steps raw 9.0V to 5.0V using internal circuitry. -! Large ripple and decoupling capacitors are used to prevent large fluctuations in supply voltage
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Let’s Start Building -! Orient board as shown for the duration of this kit construction unless indicated otherwise -! Raise your hand for assistance if any issues arise
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Step 1: 3 pin header -! Mount the header pin on the top side of the board and solder on the back side -! The header is located in the lower left side of the PCB -! Consult the following pictures for examples of this
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Step 1: 3 pin header (before)
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Step 1: 3 pin header (after close up)
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Step 1: 3 pin header (after) -! Solder from bottom of board
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Step 2: D9 -! Mount and solder D9 into the appropriate place on the PCB -! Note the stripe on the diode and the relevant stripe on the PCB and align appropriately -! Consult the following pictures for examples of this
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Step 2: D9 (after)
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Step 3: C3 and C9 -! Mount and solder the two large electrolytic capacitors (C3 and C9) to the appropriate location on the PCB. -! **These capacitors have polarity and the negative clearly marked by the packaging (see photo)** -! Match (-) to the negative side as shown on the board to allow the correct orientation
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Step 3: C3 and C9 (before close up)
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Step 3: C3 and C9 (before)
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Step 3: C3 and C9 (after)
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Step 3: C3 and C9 (after close up)
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Step 5: Q1 -! Find Q1 (LM7805) in the provided parts -! Voltage regulator must be bent over to lay flat on the board -! Mount the voltage regulator such that it can be bent and lay flat on the PCB -! Can pre bend in board before soldering and adjust with bending tool before soldering in place -! Now solder the voltage regulator in place 67 RockOn! 2015 RockOn 2015 Workshop
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Step 5: Q1 (bending) -! Place Q1 in the proper orientation on the PCB and bend into place in the depicted manner before soldering
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Step 5: Q1 (before)
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Step 5: Q1 (after)
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Step 5: Q1 (after close up)
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Step 5: Q1 (after edge view)
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DC Voltage Regulation– Coordinates (C1): 5.0V
Rectifying Diode
ator
g Volta
gul e Re
-! Creates a regulated 5.0V power voltage that is reverse bias protected from a diode. -! 5.0 Volt signal is created with a linear voltage regulator that steps raw 9.0V to 5.0V using internal circuitry. -! Large ripple and decoupling capacitors are used to prevent large fluctuations in supply voltage Highlight your schematic RockOn 2015 Workshop
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Low Voltage (LV) Test
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Step 6: LV Test 1st Powered Check -! Must check if ground and power (+) are connected - Set multimeter to continuity - Touch red and black probes together to get a beep - Touch (+) and (–) on board. Should not hear a beep
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Step 6: LV Test 1st Powered Check -!On the right angle 3-pin header, touch the (+)/ (red) to the middle 9V pin and the (-)/ (black) to the left GND pin -!Should not hear a beep - If you do, raise your hand
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Step 6: LV Test 1st Powered Check -! Set multimeter to the 20 V DC Voltage setting -! Find a 9V battery -! Measure voltage of 9V test battery and record
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Step 6: LV Test 1st Powered Check -! Connect to your power connector
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Step 6: LV Test 1st Powered Check -! Insert black cap into unused end to prevent possible shorting
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Step 6: LV Test 1st Powered Check -! Connect power to the circuit using the battery connector and two pin board connector already soldered
*Note that the connector will not fit very well as it is meant for a different board*
-! Match the wires of the three pin Geiger header to the correct power and ground wires on the battery wires as shown -! *Red is middle pin, black is left most pin*
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Step 6: LV Test 1st Powered Check -! Touch the red (positive) lead to the leftmost pin of the voltage regulator -! Touch the black (negative) lead to the GND test point in the upper left corner of the PCB
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Step 6: LV Test 1st Powered Check -! Multimeter should read ~5.0 Volts with little deviation depending on component tolerances and battery charge -! If so, remove power and wait -! If not, check the orientation of D9, C3 and C9 and/or raise your hand.
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Step 6: LV Test 1st Powered Check -! Complete your Subsystem Acceptance Checklist
Yes 9.0 4.92
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Current Sub System: Geiger Counter Sub Systems: DC Voltage Regulation Oscillator High Voltage (Unregulated) High Voltage Regulation Output Pulse 84 RockOn! 2015 RockOn 2015 Workshop
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Oscillator Circuit – Coordinates (A1): Current limiting resistor
-! U1 creates an oscillatory square wave to switch the primary windings of the mini step-up transformer on and off. -! The speed of this oscillation is determined from the RC circuit design, which is approximately 50 KHz. 85 RockOn! 2015 RockOn 2015 Workshop
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Oscillator Circuit – Coordinates (B1): RC Timer Resistor
-! C1 acts like a switch. Because of the setup of the inverting buffer pins, the circuit will form a rectified oscillating square wave at the power FET.
DC
w
Do Pull
r
isto
s n Re
Pendulum 86 RockOn! 2015
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Step 7: U1 Socket -! Orient the 16 pin socket to match the notch on the PCB -! Solder the corners of the chip socket in to tack down -! Solder the remaining 12 pins and retouch the four corners if needed -! Do not insert the chip
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Step 7: U1 socket before
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Step 7: U1 socket before (close up)
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Step 7: U1 socket after
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Step 7: U1 socket after (close up)
NOTCH
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Step 8: D1 (1N914) -! Locate D1 in the provided parts -! Orient the diode to match the orientation on the PCB -! Mount and solder the diode into place -! Note the polarity and line on the diode, match to the PCB silkscreen
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Step 8: D1 (1N914) before
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Step 8: D1 (1N914) after
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Step 8: D1 after (close up)
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Step 9: C1 and C2 -! Mount and solder C1 and C2 into the appropriate places on the PCB -! These capacitors are not polarized, so the orientation of mounting will not compromise performance -! C1 (0.0047 µF @ 50V)
C1
-! C2 (0.01 µF @ 16V)
C2 96 RockOn! 2015 RockOn 2015 Workshop
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Step 9: C1 and C2 (before)
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Step 9: C1 and C2 (after)
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Step 9: C1 and C2 after (close up)
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Step 10: R1, R2, R3 -! Mount and solder R1, R2 and R3 into the appropriate location on the PCB
D1
-! This resistors are not polarized -! R1 = 4.3K -! ( Yellow-Orange-Red)
-! R2 = 15K -! ( Brown-Green-Orange)
-! R3 = 5.6K -! ( Green-Blue-Red)
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Step 10: R1, R2, R3 before
D1
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Step 10: R1, R2, R3 before (close up)
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Step 10: R1, R2, R3 after
D1
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Step 10: R1, R2, R3 after (close up)
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Oscillator Circuit – Coordinates (A1): Current limiting resistor
-! U1 creates an oscillatory square wave to switch the primary windings of the mini step-up transformer on and off. -! The speed of this oscillation is determined from the RC circuit design, which is approximately 50 KHz. 105 Highlight your schematic RockOn 2015 Workshop
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Oscillator Circuit – Coordinates (B1): -! C1 acts like a switch. Because of the setup of the inverting buffer pins, the circuit will form a rectified oscillating square wave at the power FET.
RC Timer Resistor
ull CP
D
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isto
s n Re
Dow
-! This 16 pin chip is shown in multiple places to indicate where in the circuit it operates. 106
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Current Sub System: Geiger Counter Sub Systems: DC Voltage Regulation Oscillator High Voltage (Unregulated) High Voltage Regulation Output Pulse 107 RockOn! 2015 RockOn 2015 Workshop
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High Voltage (Unregulated) – Coordinates (A2): -! Q2 (power MOSFET) stabilizes the voltage switching on the primary windings of T1 more efficiently than the raw oscillator output.
Power MOSFET
-! D2 and D3 serve as a doubling full wave -! Mini step-up transformer uses the rectification circuit for the HV AC output to HV oscillator circuit output to create DC with some voltage the high voltage (HV) needed for ripple. the operation of the Geiger counter.
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High Voltage (Unregulated) – Coordinates (A2, A3): -! Rectified HV is received after the HV AC passes through the two rectifying diodes.
-! Why is there still voltage ripple present?!
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High Voltage (Unregulated) – Coordinates (A2, A3): -! Using a HV capacitor on each output line for the proper voltage, the voltage ripple is smoothed
Rectifying Diode
-! The circuit is now nearing the desired HV DC supply for the Geiger Tube
-! Each discharges with a falling peak and recharges with a rising peak 110 RockOn! 2015
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High Voltage (Unregulated) – Coordinates (A2, A3):
-! The circuit is now at the desired HV DC supply for the Geiger Tube -! This technique is used frequently in power electronics, and most electronics can handle a small variation in voltage 111 RockOn! 2015 RockOn 2015 Workshop
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Step 11: T1 CAUTION!!! -! Locate T1 (a four pronged transformer) among your parts -! This component is extremely fragile, composed of very small gauge wire twined around a few nodes. The wires are surrounded by brittle plastic connected to four pins. -! If excess force is applied to these metal pins the plastic will break and sever the small wiring within the transformer 112 RockOn! 2015 RockOn 2015 Workshop
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Step 11: T1 CAUTION!!! -! Use CAUTION! The transformer will fit into the PCB in one orientation only -! **The transformer may not fit perfectly. Try a dry fit at first to note which leads may need bending. -! If a lead does need bending, use care to slowly and gently bend the leads with the plastic probing tool or a pair of needle nose pliers
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Step 11: T1 CAUTION!!! -! Do not force the transformer to be flush with the PCB or it WILL break and render it useless
T1
-! Mount and solder T1 to the PCB -! Match the dot on the transformer to the dot on the PCB
Example of worse case flushness to board of T1. 114 RockOn! 2015 RockOn 2015 Workshop
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Step 11: T1 before
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Step 11: T1 before (close up)
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Step 11: T1 after
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Step 11: T1 after (close up)
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Step 12: Q2 IRF830 -! Q2 transistor must be bent over to lay flat on the board
Mounting Hole
-! Mount the transistor such that it can be bent and lay flat on the PCB before soldering in place -! This process should be similar to the 5.0V regulator soldered earlier -! Do not cover the mounting hole
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Step 12: Q2 before
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Step 12: Q2 before (close up)
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Step 12: Q2 after
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Step 12: Q2 after (close up)
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Step 13: C4 and C5 -! Locate the two high voltage rectifying capacitors (C4 and C5) in your kit contents -! Mount and solder these capacitors in your PCB as designated -! These capacitors are not polarized
C4
C5 124 RockOn! 2015 RockOn 2015 Workshop
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Step 13: C4 and C5 before
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Step 13: C4 and C5 after
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Step 13: C4 and C5 after (close up)
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Step 14: D2 and D3 (1N4007) -! Locate two of the black HV diodes (D2 and D3) in your kit -! Mount and solder these diodes in your PCB as designated -! Ensure the line on the diode matches the line on the PCB silkscreen -! These diodes are polarized! 128 RockOn! 2015 RockOn 2015 Workshop
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Step 14: D2 and D3 before
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Step 14: D2 and D3 after
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Step 14: D2 and D3 after (close up)
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Step 15: U1 MC14049BCP -! Locate the inverting buffer (U1) in your kit contents and mount to the 16 pin chip socket -! Make sure to match the notch on the chip to the notch on the socket and PCB silkscreen -! Installing the chip backwards could damage your PCB 132 RockOn! 2015 RockOn 2015 Workshop
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Step 15: U1 before
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Step 15: U1 after
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Step 15: U1 after close up
NOTCH
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High Voltage (Unregulated) – Coordinates (A2): -! Q2 (power MOSFET) stabilizes the voltage switching on the primary windings of T1 more efficiently than the raw oscillator output.
Power MOSFET
-! D2 and D3 serve as a doubling full wave -! Mini step-up transformer uses the rectification circuit for the HV AC output to HV oscillator circuit output to create DC with some voltage the high voltage (HV) needed for ripple. the operation of the Geiger counter. Highlight your schematic RockOn 2015 Workshop
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High Voltage (Unregulated) – Coordinates (A2, A3): -! Rectified HV is received after the HV AC passes through the two rectifying diodes.
-! Why is there still voltage ripple present?!
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High Voltage (Unregulated) – Coordinates (A2, A3): -! Using a HV capacitor on each output line for the proper voltage, the voltage ripple is smoothed.
Rectifying Diode
-! The circuit is now nearing the desired HV DC supply for the Geiger Tube!
-! Each discharges with a falling peak and recharges with a rising peak. 138
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High Voltage (HV) Regulation Test 139
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Step 16: HV Test 1st Powered Check -! Locate the provided voltmeter and set to the 1,000 V DC setting
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Step 16: HV Test 1st Powered Check -! Find a 9V battery and apply power to the circuit
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Step 16: HV Test 1st Powered Check -! Touch the red (positive) lead to the to the test point near C5 and D2 -! Touch the black (negative) lead to the GND test point as before
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Step 16: HV Test 1st Powered Check -! Voltmeter should read between 550-850 Volts depending on component tolerances -! If so, remove power and prepare for the next -! If not; check the orientation of the diodes on the board, continuity of soldering joints, and raise your hand
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Step 16: HV Test 1st Powered Check -! Complete your Subsystem Acceptance Checklist
764
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Current Sub System: Geiger Counter Sub Systems: DC Voltage Regulation Oscillator High Voltage (Unregulated) High Voltage Regulation Output Pulse 145 RockOn! 2015 RockOn 2015 Workshop
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High Voltage Regulation – Coordinates (A3): -! Regulated 500V DC for the Geiger tube is completed by three Zener Diodes in series. -! Zener Diodes are a low-cost voltage regulation. -! Conduct to a certain voltage. -! Dissipate extra voltage as current.
Rectifying Diode
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Step 17: D4, D5, D6 -! Locate D4, D5, and D6 in the provided parts -! Match the black line to the line on the PCB as shown
D4
-! Mount and solder these diodes in their required locations on the PCB -! **When bending make note of the wider spacing of the holes for mounting these diodes.**
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Step 17: D4, D5, D6 before
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Step 17: D4, D5, D6 after
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Step 17: D4, D5, D6 after (close up)
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High Voltage Regulation – Coordinates (A3): -! Regulated 500V DC for the Geiger tube is completed by three Zener Diodes in series. -! Zener Diodes are a low-cost voltage regulation. -! Conduct to a certain voltage. -! Dissipate extra voltage as current.
Rectifying Diode
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High Voltage (HV) Regulation Test 152
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Step 18: HV Test 2nd Powered Check -! Locate the provided voltmeter and set to the 1,000 V DC setting
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Step 18: HV Test 2nd Powered Check -! Find a 9V battery and apply power to the circuit
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Step 18: HV Test 2nd Powered Check -! Touch the red (positive) lead to the junction of C5 and D2 -! Touch the black (negative) lead to the GND test point as before
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Step 18: HV Test 2nd Powered Check -! Multimeter should read ~500 V with ± 30V deviation depending on component tolerances and battery charge -! If so, remove power and prepare for the next step -! If not, check the orientation of D4 and D6 and raise your hand
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Step 18: HV Test 2nd Powered Check -! Complete your Subsystem Acceptance Checklist
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Current Sub System: Geiger Counter Sub Systems: Oscillator High Voltage (Unregulated) DC Voltage Regulation High Voltage Regulation Output Pulse 158 RockOn! 2015 RockOn 2015 Workshop
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Output Pulse Circuit -! Output is sent through many different indicators for each radioactive particle detected -! Audio is sent through a multi stage inverter to give extra current needed through the speaker amplifier transistor Q3 -! Each pulse will activate the speaker and result in an audible click
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Output Pulse Circuit -! Original pulse is fed into a 555 timer configured in monostable mode, meaning the timer is only stable in one mode -! Mode allows for a trigger event detection, i.e. a Geiger counter radiation event pulse -! 555 timer uses this trigger to lengthen the short pulse width to a wider, more detectible pulse for the speaker setup, digital output, and visual output 160 RockOn! 2015 RockOn 2015 Workshop
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Output Pulse Circuit – Coordinates (B2-C4): Inverting Buffer Regulating Zener Diode 5.1V
Current Limiting Resistor
VCC Supply
Current Sourcing Buffer
Rectifier Diode
Amplifying NPN Transistor
Indicator LED
Current limiting resistor
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Output Pulse Circuit – Coordinates (A3 & A4):
Current spike filter
Current limiting resistor
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Step 19: R4, R5, and C6 -! Locate in your kit contents
R4
-! R4 (Blue Gray Yellow) -! R5 (Brown Black Blue) -! C6 (Orange Ceramic)
R5 C6
-! Mount and solder these resistors in the required location on the PCB -! Also mount and solder this capacitor in the required location on the PCB
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Step 19: R4, R5, and C6 before
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Step 19: R4, R5, and C6 after
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Step 19: R4, R5, and C6 after (close up)
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Step 19: R4, R5, and C6 after (close up)
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Step 20: D8 (1N75) -! Locate D8 (1N75) in the provided parts -! Note the black line and line up with the silkscreen as before -! Mount and solder this diode in the required location on the PCB
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Step 20: D8 before
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Step 20: D8 after
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Step 20: D8 after (close up)
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Step 21: Q3 NPN Transistor -! Locate Q3 (2N3904) in the provided part -! Mount and solder this transistor in the required location on the PCB
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Step 21: Q3 NPN Transistor before
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Step 21: Q3 NPN Transistor after
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Step 21: Q3 NPN Transistor after (close up)
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Step 22: U2 8 Pin Socket -! Locate the 8 pin chip socket in the provided parts -! Note the location of the notch and align accordingly -! Mount and solder this chip socket in the required location on the PCB -! Do not install chip 176 RockOn! 2015 RockOn 2015 Workshop
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Step 22: U2 8 Pin Socket before
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Step 22: U2 8 Pin Socket after
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Step 22: U2 8 Pin Socket after (close up)
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Step 23: C8, C7, and R7 -! Locate C7, C8, and R7 in the provided parts -! Note the location of these components -! Mount and solder these components in the proper location on the PCB
Brown Green Yellow C7
C8
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Step 23: C8, C7, and R7 before
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Step 23: C8, C7, and R7 after
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Step 23: C8, C7, and R7 after (close up)
NOTCH
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Step 24: D10 (1N914) -! Locate D10 in the provided parts -! Note the location of this component and its polarity -! Mount and solder this component in the proper location on the PCB
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Step 24: D10 (1N914) before
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Step 24: D10 (1N914) after
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Step 24: D10 (1N914) after (close up)
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Step 25: Speaker -! Locate the speaker in the provided parts -! Note the location of this component and its polarity -! Mount and solder this component in the proper location on the PCB
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Step 25: Speaker before
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Step 25: Speaker after
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Step 26: D7 and R9 D7
-! Polarity of LEDs
+ R9
Flat side is Negative
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Step 26: D7 and R9 D7
-! Locate the components in the provided parts -! Note the location of each component and its polarity -! Mount and solder each component in the proper location on the PCB
+ R9
Flat side is Negative
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Step 26: D7 and R9 before
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Step 26: D7 and R9 after
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Step 26: D7 and R9 after (close up)
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Step 27: R8 -! Locate R8 (Yellow Purple Brown) in the provided parts -! Mount and solder this resistor in the required location on the PCB
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Step 27: R8 before
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Step 27: R8 after (close up)
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Step 28: Installing the 555 Timer IC (before) -! Locate the 555 timer IC in your parts and install in the 8 pin socket -! Be sure to match the notch to the socket and PCB notch NOTCH
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Step 28: Installing the 555 Timer IC (after)
NOTCH
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Output Pulse Circuit – Coordinates (B2-C4): Inverting Buffer Regulating Zener Diode 5.1V
Current Limiting Resistor
VCC Supply
Current Sourcing Buffer
Rectifier Diode
Amplifying NPN Transistor
Indicator LED
Current limiting resistor
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Output Pulse Circuit – Coordinates (A3 & A4):
Current spike filter
Current limiting resistor
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Geiger Tube Installation
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Step 29: Geiger Mueller (GM) Tube -! Find the GM Tube in the provided parts
+
-! It is polarized. Note the polarity on the part and the PCB
-
-! On the tube the thin wire is GM negative and the large wire is GM positive All tubes were tested prior to and after coating 204 RockOn! 2015 RockOn 2015 Workshop
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Step 29: What’s that on the end of the tube?! -! Tube is filled with an inert gas to promote ionization in the presence of radiation -! Tube also has a very fragile, thin mica window to allow alpha particles to pass through. -! Window will blow out in low pressure environments -! Epoxy prevents blowout, but also eliminates alpha particles from detection
Skin of the rocket will block all alpha radiation 205 RockOn! 2015
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Step 29: GM Tube (Precautions) -! Do not overheat the GM tube -! When soldering, it can overheat easily -! Avoid the glass fill knob at the rear of the tube -! Shatter this, and your tube won’t work
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Step 29: GM Tube-Positive Wire -! Find and strip " inch from both ends of the provided Geiger wire (~6 in) -! Solder one of the stripped edges to the positive end of the GM tube as shown. -! Be CAREFUL! Don’t let the iron linger longer than 5 seconds before giving the tube 10-15 seconds to cool. -! DO NOT SOLDER THE CLIP ON POST OF THE TUBE EVEN THOUGH IT’S LOOSE
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Step 30: GM Tube-PCB Wiring -! Orient the tube on the bottom of the board such that the glass element is away from the board -! Loop the thin ground wire into the GM – hole -! Solder the thin wire through the GM – hole going down through the top of the PCB -! Be CAREFUL! The thin wire will snap if bent too much or at a large angle
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Step 30: GM Tube-PCB Wiring
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Step 30: GM Tube-PCB Wiring - Add electrical tape to prevent potential shorts.
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Step 30: GM Tube-PCB Wiring -! Solder, from the top, the free end of the wire into GM+ coming from the bottom of the board up through the hole
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Step 30: GM Tube-PCB Wiring -! Strip both ends of the white wire provided. Solder this wire in the very end of the provided GM Tube mounting holes for added support
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Step 30: GM Tube-PCB Wiring
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Step 31: GM Tube-PCB Lacing -! Find the thin wiring in the provided parts -! Use this wire like shoelaces for the mounting array on the GM PCB -! Run the wire through the first two holes for each end as shown -! Loose ends of the wire should extend upward through the board 214 RockOn! 2015 RockOn 2015 Workshop
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Step 31: GM Tube-PCB Lacing
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Step 31: GM Tube-PCB Lacing -! Begin a cross hatch method above and below the board as if you are lacing a tennis shoe -! When you get to the end, loop back following a similar pattern until about 6 inches of the wire remains. -! Tie off the wire in the middle of the mounting array
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Step 31: GM Tube-PCB Lacing
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Step 31: GM Tube-PCB Lacing -! Tie a double square knot when the lacing of the GM tube is complete DOUBLE SQUARE KNOT EXAMPLE
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Final Product
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Final Product
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Step 32: Background Testing -! Attach power to the circuit again -! The Geiger counter should randomly blink detecting usually 12-14 counts per minute depending on sources in the area and shielding
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Step 32: Background Testing -! Complete your Subsystem Acceptance Checklist
13
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Final Product Testing -! To really test, we need a radioactive source…
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Smoke Detector Modification 224
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Overview: -!The Geiger counter that you assembled can detect all three types of radiation: alpha, beta, and gamma. -!To test the Geiger counter, we will obtain a radioactive source from the common household smoke detector. -!The common household smoke detector uses a very small amount of Americium 241 to detect smoke particles in the air. 225 RockOn! 2015 RockOn 2015 Workshop
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Safety:
-! According to the World Nuclear Association [1], Americium 241 is an alpha emitter that also emits some low energy gamma rays. -! “Even swallowing the radioactive material from a smoke detector would not lead to significant internal absorption of Am-241, since the dioxide is insoluble.” [1] -! Caution: Although the sample is rather benign, do take caution to keep it away from your face at all times. -! Caution: Also make sure that you wash your hands before eating if you handle the sample. 226 RockOn! 2015 RockOn 2015 Workshop
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Step A: Opening the detector housing Opening the detector housing and remove the lid. Use the side cutters as a fulcrum.
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Step B: Visually inspect the detector PCB
Radiation Source
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Step C: Separate the PCB from the detector housing Clip wires
Bend inward and remove PCB from housing.
Close up
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Step C: Separate the PCB from the Detector Housing
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Step D: Remove Radiation Source
Remove the solder from these two locations using your soldering iron and solder sucker
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Step E: The Source is Ready
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Step E: The Source is Ready The Source
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Final Product: Testing 234
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Step 33: Radiation Testing -! Attach power to the circuit again.
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Step 33: Radiation Testing -! Acquire the provided alpha particle source (taken from a smoke detector) -! Notice a large jump in the frequency of counts -! Each count represents the detection of a radioactive particle by the Geiger counter
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Step 33: Radiation Testing -! Complete your Subsystem Acceptance Checklist
13 130
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Coronal Discharge
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Coronal Discharge: An Overview -! Coronal discharge occurs in low pressure environments with high voltages present. -! The air around a high potential (high voltage) will become a conductor and emit a bluish glow (plasma). -! This plasma will cause adverse effects for the component as well as neighboring parts. -! The plasma is a bluish-purple and is visible under normal lighting. (see images)
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Coronal Discharge: An Example RockOn! Geiger counter seen through a vacuum chamber.
Area of interest near back of D4-D6
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Coronal Discharge: An Example Geiger counter seen through a vacuum chamber
Glow of coronal discharge
Close-up
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Coronal Discharge: The solution -! Coronal discharge is detrimental to parts. -! Dangerous to other payloads on the rocket. -! To mitigate these risks, we will add conformal coating to the board to prevent coronal discharge. -! **Note: We will be in a pressurized environment on this flight so this is not necessary, but is a good practice especially with space applications.
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Conformal Coating
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Current Sub System: Geiger Counter Sub Systems: Oscillator High Voltage (Unregulated) DC Voltage Regulation High Voltage Regulation Output Pulse 244 RockOn! 2015 RockOn 2015 Workshop
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Step 1: Board Prep -! Take the board to a well ventilated area (we will be outside). -! Put on safety glasses and rubber gloves. -! Place the board face up on the prepared protected surface. -! Shake the bottle lightly and open it. -! MAKE SURE there is no power on the board.
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Step 1: Board Prep HV Section
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Step 2: Begin Coating -! Dip the brush in and begin application coating the entire top side of the board with an even layer. -! Re-dipping the brush every 2-3 strokes is recommended. -! The board should look glossy under lighting where coating has been applied. -! If any safety concerns occur consult the MSDS provided. 247 RockOn! 2015 RockOn 2015 Workshop
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Step 3: Detail Coating (chips in sockets) -! Coat the chips as well, as long as they are secured in their sockets.
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Step 3: Detail Coating (underneath components) Apply underneath closely oriented parts like diodes, capacitors, and resistors in this manner.
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Step 4: Detail Coating (between components) Apply between closely oriented parts Use smooth strokes (about 3 per dip) 250 RockOn! 2015 RockOn 2015 Workshop
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Step 5: Clear out mounting holes and test points Clear the conformal coating from the 4 mounting holes as necessary
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Step 6: Backside Coating -! Flip the board over using minimal contact with the currently curing coating. -! Coat the entire backside as desired using the same 3 stroke per dip rule.
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Step 6: Backside Coating Apply across the whole board, make sure the whole PCB is coated thoroughly.
Note the glossy look of the coated board.
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Step 7: Touch-ups -! Visually inspect the board to ensure it is coated thoroughly using the special lights and a staff member. -! Make any touch-ups as necessary, ensuring there are no bubbles underneath parts. -! You may add additional coating to the HV section if you desire, but one coat is enough to do the job.
HV Section Conformal coating over tape?
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Step 7: Drying and Clamping -! Flip the board over and attach to helping hands where shown. -! This area is not HV and won’t affect the cure if clamped here
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Step ?: Make Sures -! Make sure that these two capacitors do not have too much coating on top surface -! May interfere with payload plate above during integration 256 RockOn! 2015 RockOn 2015 Workshop
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Step ?: Make Sures -! Make sure these pins are not coated with conformal coating.
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Step ?: Make Sures -! When completed, please leave all conformal coated materials (gloves, brushes, paper towels) in trash outside -! Leave your board, labeled with your kit number, in the entryway table.
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Geiger Counter Background 259
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Radiation: Overview -! Radiation is generally viewed as harmful to space payloads. -! While some projects purposely expose parts to the saturated Van Allen belts to investigate the effects of high energy particles, some projects must avoid harmful doses at all costs. -! Sparse data has been collected from suborbital airspace. -! This payload will allow for a large collection of data sets.
Van Allen Belts: www.nasa.gov
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Radiation: Effects -! Single event phenomenon (SEP), burnouts and bit flips can cause damage to solid state devices aboard a space payload. -! An understanding of dose levels is ideal to plan a mission to sub-orbital altitudes, especially with sensitive optics or microprocessors.
SEP diagram: www.aero.org/ 261 RockOn! 2015
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Radiation: Effects -! There are three types of radioactive emissions: -! Alpha - the least penetrating form of radiation, can be stopped with a piece of paper or a few inches of air. -! Beta-rays are more penetrating than alpha-rays -! Gamma-rays are the most penetrating form of radiation. Often produced in conjunction with alpha or beta-rays, they can penetrate several inches of steel or hundreds of feet in air.
Particle comparison: www.freedomforfissi on.org.uk
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Radiation: A General Trend -! Radiation levels roughly double every 5000 feet in altitude, so at sea level dosage will be roughly # the level observed in Denver, Colorado.
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Radiation: A General Trend -! However, radiation levels do depend on the level of cosmic radiation, effective shielding, and any ground or building materials containing radioactive materials. -! In general, at sea level; you should see 12-14 counts per minute. -! This device has resolution to 2 µs. Which indicates it cannot detect particle events closer than 2 µs to each other.
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Radiation: A General Trend
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Radiation: Dosage and Limits -!Max dose for occupational workers (Nuclear Power) 5 Rem/yr (max exposure to retina). [2]
Shielding can drastically reduce the observed dose. Be sure to wear safety glasses when handling the material.
-!Max dose recommended for the general public 100 mRem from a high energy source over a short time frame. [2] -!An average American receives 360 mRem/yr from natural background and manmade sources. [2] [2] http://www.jlab.org/div_dept/ train/rad_guide 266 RockOn! 2015
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Radiation: Comparisons -!A typical radiation dose from a chest x-ray is about 10 mRem per x-ray (Gamma exposure) [2] -!Consumer products contain radiation, such as: smoke detectors, and lantern mantles. This dose is relatively small as compared to other naturally occurring sources of radiation and averages 10 mRem in a year (Alpha exposure). [2]
20th Century Fox ©
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Radiation: Conversions -! Generally, 75 counts per minute (CPM) is equivalent to 1 mRem/ hr. -! Therefore, 4500 CPM is roughly equivalent to 1 mRem -! A source from a smoke detector makes up 2.8% of the yearly average expected dose, which is .027 mRem/day or .0012 mRem/hr -! These numbers shouldn’t alarm you, an average person receives 1 mRem per day.
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