OR
OR
OPA2340PA
| Image (not to scale, borrowed from Digikey) | Quantity | Part Name and Digikey Link | Name on PCB | Description and Notes |
|---|---|---|---|---|
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OR |
1 | MCP6282-E/P-ND
OR OPA2340PA |
OPAMP | Low voltage operation, low current draw, and a high slew rate are requirements for this op-amp. The second one has these, but is expensive. The first doesn't have as high a slew rate, so it doesn't amplify the noise as well, but it seems to do an acceptable job since we use both op-amps. |
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1 | ATTINY24V-10PU | attiny24 | The ATtiny24 has the right number of IO pins for the job. This is the low voltage version. |
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1 | MMBT3904 | MMBT3904 | A surface mount version of the venerable 2N3904 NPN transistor. Other transistors would probably work, but the value of R2 might need to change. |
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1 | ZXRE1004FFTA | ZXRE1004 | The voltage reference (fake zener diode) that provides the random noise for this device. |
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1 | LTS-4802BJR-H1 | 7seg | A 7 segment LED display which puts out a fair amount of light for the current it draws. |
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1 | EVL-HFAA01B24 | P | A 20K linear thumbwheel potentiometer. |
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1 | FSM2JSMA | SW1 | A surface mount tact switch (the dimensions are important -- many switches will not fit). |
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1 | EVQ-PAE04M | SW2 | A through hole tact switch (the dimensions are important -- many switches will not fit). |
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1 | 3003 | The holder for the 20mm coin battery. We don't need a separate bottom holder -- the pad is part of the PCB. | |
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4 | 399-4151-ND | C1-C4 | .1μF ceramic capacitor. |
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1 | CFR-12JB-100K | R1 | 100kΩ 1/6W resistor. |
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1 | CFR-12JB-470R | R2 | 470Ω 1/6W resistor. |
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1 | CFR-12JB-1M0 | R3 | 1MΩ 1/6W resistor. |
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2 | CFR-12JB-10K | R4,R5 | 10kΩ 1/6W resistor. |
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7 | CFR-12JB-1K2 | R6-R12 | 1.2kΩ 1/6W resistor. |
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1 | CA-4, 2 BLACK | The case. Some other colors are available. | |
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1 | P189-ND | 3V 20mm coin battery | |
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1 | The PCB |