Bill of Materials
Here’s a complete bill of materials for this project. Where a component is available from Farnell I’ve included the order code.
| Designator | Value | Quantity | Footprint | Description | Farnell Order Code | Notes |
|---|---|---|---|---|---|---|
| C1, C2, C6, C7, C8, C9, C11, C13, C14 | 100n | 9 | 2.54mm lead spacing | Ceramic capacitor | 2309020 | |
| C3 | 22u 16v | 1 | 2mm lead spacing | Polarized Capacitor (Radial) | 1870976 | |
| C4 | 220u | 1 | 2.5mm lead spacing | Polarized Capacitor (Radial) | 1902883 | |
| C5 | 220u | 1 | 2.5mm lead spacing | Polarized Capacitor (Radial) | 1902883 | |
| C10 | 10u | 1 | 2mm lead spacing | Polarized Capacitor (Radial) | 1902913 | |
| C12 | 1u | 1 | 5.08mm lead spacing | Capacitor | 2112910 | 1 |
| D1, D7 | 1N4007 | 2 | DO-41 | 1 Amp General Purpose Rectifier | 2317417 | 2 |
| D2 | 1 | LED-3MM | 3mm LED | 3 | ||
| D3 | 1 | LED-3MM | 3mm LED | 3 | ||
| D4 | 1 | LED-3MM | 3mm LED | 3 | ||
| D5 | 1 | LED-3MM | 3mm LED | 3 | ||
| D6 | SR150 | 1 | DO-204AL | Schottky Rectifier | 1861420 | |
| FB1 | BLM18PG221SN1D | 1 | AXIAL-0.3 | Inductor | 2292304 | |
| K1 | OJE-SS-112HMF,F000 | 1 | Relay TE OJ/OJE | Single-Pole Single-Throw Relay | 1891668 | |
| L1 | RLB0914-331KL | 1 | RADIAL 5x9x9.5 | Inductor | 2309243 | |
| L2 | RLB0712-100KL | 1 | RADIAL 10×7.2×3 | Inductor | 2434811 | |
| P1 | Edge connector | 1 | 2×25 | 2.54mm pitch, 5.08mm row spacing | 4 | |
| P2 | PM5.08/2/90 | 1 | PCB terminal block – 2 pin | WEIDMULLER PM5.08/2/90 | 1131855 | 5 |
| P3 | PM5.08/2/90 | 1 | PCB terminal block – 2 pin | WEIDMULLER PM5.08/2/90 | 1131855 | 5 |
| P4 | PM5.08/2/90 | 2 | PCB terminal block – 2×2 pin | WEIDMULLER PM5.08/2/90 | 1131855 | 5 |
| P5 | Fan header | 1 | HDR1X3 | Header, 3-Pin | 588581 | |
| P6 | 1 | 2.54mm | Header, 4-Pin | 6 | ||
| P7 | 1 | 2.54mm x 2 | Header, 5-Pin, Dual row | 6 | ||
| Q1, Q2, Q3, Q4 | BS170 | 4 | TO-92 | N-Channel MOSFET | 1017687 | |
| R1, R9 | 680 | 2 | AXIAL-0.3 | Resistor | 2329545 | |
| R2, R3 | 470 | 2 | AXIAL-0.3 | Resistor | 2329531 | |
| R4, R7, R10, R12, R13, R14 | 10k | 6 | AXIAL-0.3 | Resistor | 2329474 | |
| R5, R6 | 2.2k | 2 | AXIAL-0.3 | Resistor | 2329584 | |
| R8 | 2m 1% | 1 | 2512 | Welwyn ULR2-R002FT2 | 1292491 | |
| R11 | 68k | 1 | AXIAL-0.3 | Resistor | 2329546 | |
| SW1 | PM5.08/2/90 | 3 | PCB terminal block – 3×2 pin | WEIDMULLER PM5.08/2/90 | 1131855 | 5 |
| SW2 | 1 | PCB terminal block (3 pin) | Header, 3-Pin | 7 | ||
| U1 | LM2574N-5.0/NOPB | 1 | DIP-8 | 0.5A Step-Down Voltage Regulator | 1469169 | 8 |
| U2 | INA226AIDGST | 1 | MSOP-10 | Current Sense Amplifier | 1924807 | |
| U3 | MCP9700-E/TO | 1 | HDR1X3 | MCP9700 plus fan-style header | 1332166,588581 | 9 |
| U4 | MAX7221CNG | 1 | DIP-24 | 8-Digit LED Display Driver | 10,8 | |
| U5, U7 | 03641A | 2 | 0.36″ 12 pin | 4 digit 7 segment LED common cathode | 410561X | 11 |
| U6 | ATmega328P-PU | 1 | DIP-28 | 8-bit AVR Microcontroller | 1715487 | 12,8 |
Notes
Some of the components have note numbers against them. The following numbered paragraphs correspond to a numbered note in the bill of materials table.
- 2.54mm parts can also be used if you carefully bend the leads outwards to fit the wider 5.08mm pitch.
- Any of the 1N400x series will be fine. They all cost about the same so I tend to keep a stock of the biggest one, the 1N4007 around.
- Any colour of 3mm LED will work. I’ve used amber for Power/PGOOD, white for EN and blue for VSP for no other reason than I felt like it.
- This can be a tricky one. I got the edge connector on ebay, item number 140888533934. Part 2668415 at Farnell looks like it could be persuaded to fit – the row pitch is only 0.2mm off the required 5.08mm.
- PCB terminal blocks with the 5.08mm pitch are plentiful on ebay and they slot together to form longer blocks. There’s no reason not to use the cheaper ebay blocks for the switchgear but I would stick to a quality item for the power in/out blocks (P2, P3 and P4).
- The male 2.54mm pin headers are at their cheapest on ebay.
- The 3-way 5.08mm PCB terminal blocks are available on ebay.
- I mount all my ICs in sockets. You don’t have to but if you need to replace one…
- I’ve included a 3×2.54mm header footprint for the TO-92 temperature sensor and I chose to use a 3-pin fan header as the connector. You could just as easily use male and female pin headers if you have them, or even solder the sensor wires directly to the board as the most economical method.
- The MAX7221CNG is available cheaply on ebay in lots of 5. As usual with ebay there’s a good chance of them being clones but that’s where I bought mine from and they seem to work.
- The 7-segment 0.36″ LED display is available from many ebay sources. Make sure it’s a common cathode configuration. These displays all seem to share a common pinout, but just in case click here to see the datasheet for the one that I bought.
- You can probably buy an Arduino clone on ebay from China with an Atmega328P on board for less than Farnell will charge you for one piece of the IC alone.
