# 12V 555 Ignition Coil Driver ## Description 12 V NE555 astable ignition-coil driver using an IRF840 MOSFET low-side switch with gate conditioning, decoupling, input/output connectors, and flyback clamp protection. ## Project Details - **Owner:** jmel811 - **Created:** 6/10/2026 - **Last Updated:** 6/10/2026 - **Visibility:** Public ## Key Components ### D1 — [P6KE200A](https://www.flux.ai/jecstronic/p6ke200a~bik.md) - Role Details: 200 V unidirectional TVS from MOSFET drain/coil low node to GND; keeps clamp below IRF840 500 V VDS while avoiding slow freewheel-only behavior - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: STMicroelectronics - Role: Flyback Clamp - Manufacturer Part Number: P6KE200A - Part Type: Diode - Datasheet URL: https://www.st.com/content/ccc/resource/technical/document/datasheet/1a/3b/f2/a9/96/72/49/ca/CD00000720.pdf/files/CD00000720.pdf/jcr:content/translations/en.CD00000720.pdf **Pins:** - A [pin 2] - K [pin 1] ### D2 — [1N4007](https://www.flux.ai/jecstronic/1n4007~7vb.md) - Datasheet URL: https://www.nteinc.com/specs/original/1N4001_07.pdf - Role: Input Protection - Manufacturer Name: NTE Electronics, Inc - Role Details: Series diode on +12 V input feeding 555/control rail; 1 A DO-41 through-hole diode - Manufacturer Part Number: 1N4007 - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Diode **Pins:** - anode [pin 2] - cathode [pin 1] ### J1 — [236-102](https://www.flux.ai/cherepanyadima/236-102~pe.md) - Symbol Style: Parametric - Role Details: 2-position screw terminal for +12 V and GND input - Part Type: Connector - Manufacturer Part Number: 236-102 - Manufacturer Name: https://wago.priintcloud.com/datasheets/236-102/en/ - Role: Power Input - Datasheet URL: https://wago.priintcloud.com/datasheets/236-102/en/ **Pins:** - ~ [pin L1] - ~ [pin L2] ### J2 — [236-102](https://www.flux.ai/cherepanyadima/236-102~pe.md) - Datasheet URL: https://wago.priintcloud.com/datasheets/236-102/en/ - Role Details: 2-position screw terminal: coil primary high side to +12 V and low side to MOSFET drain - Manufacturer Name: https://wago.priintcloud.com/datasheets/236-102/en/ - Manufacturer Part Number: 236-102 - Part Type: Connector - Role: Coil Output - Symbol Style: Parametric **Pins:** - ~ [pin L1] - ~ [pin L2] ### Q1 — [IRF840](https://www.flux.ai/lcsc/irf840~0s9p.md) - Manufacturer Part Number: IRF840 - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/1912111437_Foshan-Blue-Rocket-Elec-IRF840_C358409.pdf - Part Type: MOSFETs - JLCPCB Part Class: Extended Part - Manufacturer Name: BLUE ROCKET(蓝箭) - Role Details: IRF840 N-MOSFET, 500 V VDS, 8 A at Tc=25 C; gate driven from 12 V NE555 output through resistor - Package or Case Code: TO-220-3_L10.0-W4.5-P2.54-L - LCSC Part Number: C358409 - Product Info Url: https://lcsc.com/product-detail/Others_Foshan-Blue-Rocket-Elec-IRF840_C358409.html - Role: Low-side Switch **Pins:** - D [pin 2] - G [pin 1] - S [pin 3] ### U1 — [NE555P](https://www.flux.ai/kicad-part-library/ne555p~vhf.md) - Domain: Consumer Electronics - Role: Timer - Role Details: NE555 astable oscillator at about 1 kHz; VCC range 4.5–16 V per datasheet - Manufacturer Part Number: NE555P - Manufacturer Name: Texas Instruments Inc. - Operating Voltage: 5V - Package or Case Code: DIP-8_W7.62mm - Part Type: Precision Timer - Datasheet URL: http://www.ti.com/lit/ds/symlink/ne555.pdf **Pins:** - CONT [pin 5] - DISCH [pin 7] - GND [pin 1] - OUT [pin 3] - RESET [pin 4] - THRES [pin 6] - TRIG [pin 2] - VCC [pin 8] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/jmel811/12v-555-ignition-coil-driver~fc](https://www.flux.ai/jmel811/12v-555-ignition-coil-driver~fc).* --- *Generated from [https://www.flux.ai/jmel811/12v-555-ignition-coil-driver~fc](https://www.flux.ai/jmel811/12v-555-ignition-coil-driver~fc)*