2 layers141 × 150 mm
2 layers40 × 50 mm
M254
mhorimoto/M254電圧増幅＆比較器 for CTT-10-CLS-CV-25
- Size
- 40 × 50 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 28
- Nets
- 10
- Pads
- 64
- Tracks, vias
- 105, 0
- Pours
- 1
- Routed
- Yes
- KiCad
- KiCad 8.0 (file 20240108)
- Created
- 28 Jun 2025
- Updated
- 6 Jul 2025
Overview
M254 is an open-source printed circuit board by mhorimoto, from the mhorimoto/M254 repository on GitHub. It is a 2-layer board of 40 × 50 mm with 28 parts on 10 nets, routed with 105 tracks and 0 vias.
It is built around the NJM2903D. Its parts include 8 resistors, 7 capacitors, 4 connectors and 1 IC.
Main components
1README
README.mdNJM2903_Non-inverting_comparator_circuit_with_hysteresis
Author: Masafumi Horimoto
Voltage Amplifier & Comparator for CTT-10-CLS-CV-25
Devices
Comparator NJM2903D
Simulation results
The CTT-10-CLS-CV-25 outputs 5V at 25A. If it detects 1A, it will fix the output at a 4V level if it detects a threshold of 0.2V.
Parts
28| Qty | Value | Footprint | References |
|---|---|---|---|
| 7 | 0.1uF | Capacitor_THT:C_Disc_D3.4mm_W2.1mm_P2.50mm | C1, C2, C3, C4, C5, C6, C7 |
| 2 | 10k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P2.54mm_Vertical | R3, R7 |
| 2 | 1M | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P2.54mm_Vertical | R4, R8 |
| 2 | 2k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P2.54mm_Vertical | R2, R6 |
| 2 | 47k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P2.54mm_Vertical | R1, R5 |
| 2 | 50k | Potentiometer_THT:Potentiometer_Bourns_3296W_Vertical | RV1, RV2 |
| 2 | to M304 | Connector_JST:JST_XH_B3B-XH-A_1x03_P2.50mm_Vertical | J2, J4 |
| 1 | DSS1NB3 | HOLLY2:DSS1 | FL1 |
| 1 | DSS1NB31 | HOLLY2:DSS1 | FL2 |
| 1 | NJM2903 | Package_DIP:DIP-8_W7.62mm_LongPads | U1 |
| 1 | from Sensor1 | Connector_JST:JST_XH_B2B-XH-A_1x02_P2.50mm_Vertical | J1 |
| 1 | from Sensor2 | Connector_JST:JST_XH_B2B-XH-A_1x02_P2.50mm_Vertical | J3 |
The 24 most common of 28 parts.
Questions
How big is the M254 PCB?
It measures 40 × 50 mm and has 2 copper layers, 1.6 mm thick.
What parts does the M254 use?
28 parts, built around the NJM2903D. 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 M254 KiCad files?
From the mhorimoto/M254 repository on GitHub, at the commit this page was made from: the board is M254.kicad_pcb and its schematic M254.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the M254 design in my own project?
Its repository states no licence, so its author keeps all rights: ask mhorimoto before reusing the design.
Similar boards
- 2 layers100 × 54.6 mm
- 2 layers91 × 55 mm
- 2 layers100 × 100 mm
- 2 layers44.5 × 72.7 mm
OSO SWAT C1-jig
joeycastillo/Sensor-Watch
A board replacement for the classic Casio F-91W wristwatch
28 parts2.1k - 2 layers95 × 54 mm
EinkPDA screen
TalismanDesign/PocketMage_PDA
An E-Ink PDA device using the ESP32 S3.
28 parts2kApache-2.0 - 2 layers137.2 × 41.5 mm
Breakout 64pin 176122-6-Connector
rusefi/rusefi
rusefi - GPL internal combustion engine control unit
28 parts1.2k - 2 layers45 × 45 mm
Smartbuttons
hackclub/OnBoard
💡 Join 1,000 teenagers and make your first PCB with a $100 grant!
28 parts915