# NE555 Signal Injector Timer
## Description
Welcome to your new project. Imagine what you can build here.
## Project Details
- **Owner:** circits38
- **Created:** 4/9/2026
- **Last Updated:** 4/29/2026
- **Visibility:** Public
## Key Components
### D1 — [1N5819G](https://www.flux.ai/lcsc/1n5819g~ehiz.md)
- Package or Case Code: DO-41_BD2.4-L4.7-P8.70-D0.9-RD
- Role: Flyback clamp
- Role Details: Schottky flyback clamp across T1 primary with cathode to +12V and anode to Q1 drain primary low side to reduce reverse-recovery losses and protect the MOSFET at about 33.2 kHz.
- Part Type: Schottky Barrier Diodes (SBD)
- Product Info Url: https://lcsc.com/product-detail/Schottky-Barrier-Diodes-SBD_ON-Semicon_1N5819G_ON-Semicon-ON-1N5819G_C232463.html
- Package: Through Hole
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2409302136_onsemi-1N5819G_C232463.pdf
- JLCPCB Part Class: Extended Part
- Manufacturer Part Number: 1N5819G
- Manufacturer Name: onsemi(安森美)
- LCSC Part Number: C232463
**Pins:**
- A [pin 2]
- K [pin 1]
### J1 — [Pin Header 01x01 2.54mm Vertical - Circular Pad](https://www.flux.ai/markwuflux/pin-header-01x01-2p54mm-vertical-circular-pad~vp.md)
- Package: Through Hole
- Role Details: Red Clip (Cable) terminal connected directly to the top transformer secondary leg
- Role: Output terminal
- Part Type: Connector
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- P1 [pin 1]
### J2 — [Pin Header 01x01 2.54mm Vertical - Circular Pad](https://www.flux.ai/markwuflux/pin-header-01x01-2p54mm-vertical-circular-pad~vp.md)
- Part Type: Connector
- Package: Through Hole
- License: https://creativecommons.org/licenses/by/4.0/
- Role: Output terminal
- Role Details: Black Clip (Ground Stake) terminal connected to the bottom transformer secondary leg through a 100nF series capacitor
**Pins:**
- P1 [pin 1]
### Q1 — [IRLZ44NPBF](https://www.flux.ai/jecstronic/irlz44npbf~kg9.md)
- Manufacturer Name: Infineon Technologies
- Manufacturer Part Number: IRLZ44NPBF
- Package: TO-220AB
- Role: Low-side load switch
- Role Details: IRLZ44N N-channel MOSFET driven directly by the NE555 output; source to ground, drain reserved for future 12V load switching
- Datasheet URL: https://www.mouser.com/datasheet/2/196/Infineon_IRLZ44N_DataSheet_v01_01_EN-3363447.pdf
- License: https://creativecommons.org/licenses/by/4.0/
- Part Type: Transistor
**Pins:**
- D [pin 2]
- G [pin 1]
- S [pin 3]
### T1 — [HX1188NLT](https://www.flux.ai/adrian95/hx1188nlt~he4.md)
- Manufacturer Part Number: HX1188NLT
- Datasheet URL: https://www.verical.com/datasheet/pulse-electronics-telecom-HX1188NLT-227027.pdf
- Part Type: Transformer
- Role Details: 1:1 isolation transformer with primary driven from +12V through the MOSFET drain at about 33 kHz; secondary wired to external test leads with intentional imbalance: top leg direct to Red Clip and bottom leg through 100nF series capacitor to Black Clip for common-mode leakage current injection
- License: https://creativecommons.org/licenses/by/4.0/
- Role: RF isolation transformer
- Manufacturer Name: Pulse Electronics
- Package: SMD
**Pins:**
- CMT_1 [pin 10]
- CMT_2 [pin 15]
- NC_1 [pin 4]
- NC_2 [pin 5]
- NC_3 [pin 12]
- NC_4 [pin 13]
- RCT [pin 7]
- RD- [pin 8]
- RD+ [pin 6]
- RX- [pin 9]
- RX+ [pin 11]
- TCT [pin 2]
- TD- [pin 3]
- TD+ [pin 1]
- TX- [pin 14]
- TX+ [pin 16]
### U1 — [NE555P - 518340](https://www.flux.ai/kicad-part-library/ne555p~vhf.md)
- Package: PDIP-8
- Manufacturer Name: Texas Instruments Inc.
- Role: Astable timer
- Manufacturer Part Number: NE555P
- Role Details: Provides the 555 timer core with VCC, GND, RESET, CTRL, THRESH, TRIG, DISCH, and OUT pins for the signal injector oscillator
- Datasheet URL: http://www.ti.com/lit/ds/symlink/ne555.pdf
- Package or Case Code: DIP-8_W7.62mm
**Pins:**
- CV [pin 5]
- DIS [pin 7]
- GND [pin 1]
- Q [pin 3]
- R [pin 4]
- THR [pin 6]
- TR [pin 2]
- VCC [pin 8]
*The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/circits38/ne555-signal-injector-timer~29](https://www.flux.ai/circits38/ne555-signal-injector-timer~29).*
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*Generated from [https://www.flux.ai/circits38/ne555-signal-injector-timer~29](https://www.flux.ai/circits38/ne555-signal-injector-timer~29)*