2 layers70.3 × 57.5 mm
2 layers117 × 95 mm
1 dc psu
arafat-siju/electronics-projectsA hardware-based fastest finger quiz system using digital logic ICs, featuring timer control, first-response detection, input lockout, and timeout indication.
- Size
- 117 × 95 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 50
- Nets
- 28
- Pads
- 119
- Tracks, vias
- 366, 0
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 15 May 2026
- Updated
- 17 Oct 2026
Overview
1 dc psu is an open-source printed circuit board by arafat-siju, from the arafat-siju/electronics-projects repository on GitHub. It is a 2-layer board of 117 × 95 mm with 50 parts on 28 nets, routed with 366 tracks and 0 vias.
It is built around the L7812, LM393 and BC557, with the BD135 and BD136 among its other parts. Its parts include 17 resistors, 13 diodes, 6 capacitors, 5 transistors and 3 ICs. It belongs with the power boards of this library.
Main components
5
L7812
TO-220ST0℃~+125℃@(Tj) 1 1.2A 12V 2V@(1A) 30V 71dB@(120Hz) 76uV Fixed Positive Short Circuit Protection TO-220ST Voltage Regulators - Linear, Low Drop Out (LDO) Regulators ROHSOSENVoltage Regulators - Linear, Low Drop Out (LDO) Regulators
LM393
SOP-8-16V~16V 0℃~+70℃ 2 2.5mA 250nA 2V~36V 36V 5mV 5nA Fail-safe function Open-drain SOP-8 Comparators ROHSMSKSEMIComparators
BC557
TO-921 PNP 100mA 100nA 150MHz 45V 500mW 6V 800 90mV、250mV PNP TO-92 Bipolar (BJT) ROHSDDFBipolar (BJT)
BD135
TO-126-3-55℃~+150℃ 1 NPN 1.25W 1.5A 100nA 250 45V 500mV 5V NPN TO-126-3 Bipolar (BJT) ROHSJiangsu Changjing Electronics Technology (CJ)Bipolar (BJT)BD136
TO-126-55℃~+150℃ 1 NPN 1.5A 100nA 1W 300 45V 500mV@1.5A,0.15A 50MHz 6V Independent NPN TO-126 Bipolar (BJT) ROHSHXY MOSFETBipolar (BJT)
Parts
50| Qty | Value | Footprint | References |
|---|---|---|---|
| 7 | 1N4007 | Diode_THT:D_DO-41_SOD81_P10.16mm_Horizontal | D1, D2, D3, D4, D5, D6, D13 |
| 5 | 10k | Resistor_THT:R_Axial_DIN0309_L9.0mm_D3.2mm_P12.70mm_Horizontal | R1, R6, R8, R12, R16 |
| 4 | 1k | Resistor_THT:R_Axial_DIN0309_L9.0mm_D3.2mm_P12.70mm_Horizontal | R3, R4, R5, R7 |
| 4 | LED | LED_THT:LED_D3.0mm | D7, D8, D10, D12 |
| 3 | 10uF | Capacitor_THT:CP_Radial_D5.0mm_P2.50mm | C2, C3, C4 |
| 3 | 4.7k | Resistor_THT:R_Axial_DIN0309_L9.0mm_D3.2mm_P12.70mm_Horizontal | R11, R15, R17 |
| 2 | 1N47xxA | Diode_THT:D_DO-41_SOD81_P10.16mm_Horizontal | D9, D11 |
| 2 | 2N2219 | TerminalBlock_4Ucon:TerminalBlock_4Ucon_1x03_P3.50mm_Vertical | Q3, Q4 |
| 2 | 3.3k | Resistor_THT:R_Axial_DIN0309_L9.0mm_D3.2mm_P12.70mm_Horizontal | R9, R13 |
| 2 | 5.1k | Resistor_THT:R_Axial_DIN0309_L9.0mm_D3.2mm_P12.70mm_Horizontal | R10, R14 |
| 2 | Terminal | TerminalBlock:TerminalBlock_MaiXu_MX126-5.0-02P_1x02_P5.00mm | J1, J2 |
| 1 | 0.1uf | Capacitor_THT:C_Disc_D3.0mm_W1.6mm_P2.50mm | C6 |
| 1 | 0.33uF | Capacitor_THT:CP_Radial_D5.0mm_P2.50mm | C5 |
| 1 | 10k | Potentiometer_THT:Potentiometer_Alps_RK163_Single_Horizontal | RV1 |
| 1 | 10k | Potentiometer_THT:Potentiometer_Bourns_3386F_Vertical | RV3 |
| 1 | 220 | Resistor_THT:R_Axial_DIN0309_L9.0mm_D3.2mm_P12.70mm_Horizontal | R2 |
| 1 | 4700uF | Capacitor_THT:CP_Radial_D18.0mm_P7.50mm | C1 |
| 1 | 50k | Potentiometer_THT:Potentiometer_Bourns_3386F_Vertical | RV2 |
| 1 | BC557 | TerminalBlock_4Ucon:TerminalBlock_4Ucon_1x03_P3.50mm_Vertical | Q5 |
| 1 | BD135 | Package_TO_SOT_THT:TO-126-3_Vertical | Q2 |
| 1 | BD136 | Package_TO_SOT_THT:TO-126-3_Vertical | Q1 |
| 1 | JQC-3FF-018-1Z | Relay_THT:Relay_SPDT_Hongfa_JQC-3FF_0XX-1Z | K2 |
| 1 | L7812 | Package_TO_SOT_THT:TO-220-3_Vertical | U2 |
| 1 | LM317_TO-220 | Package_TO_SOT_THT:TO-220-3_Vertical | U1 |
| 1 | LM393 | Package_DIP:DIP-8_W7.62mm_LongPads | U3 |
Questions
How big is the 1 dc psu PCB?
It measures 117 × 95 mm and has 2 copper layers, 1.6 mm thick.
What parts does the 1 dc psu use?
50 parts, built around the L7812, LM393, BC557 and BD135. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the 1 dc psu KiCad files?
From the arafat-siju/electronics-projects repository on GitHub, at the commit this page was made from: the board is DC_power_supply(0~30v)/K i CAD/1_dc-psu.kicad_pcb and its schematic DC_power_supply(0~30v)/K i CAD/1_dc-psu.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the 1 dc psu design in my own project?
Its repository states no licence, so its author keeps all rights: ask arafat-siju before reusing the design.
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