TTL-SIREN
About the TTL-SIREN PCB
TTL-SIREN is an open source PCB design by Gabouin, published on GitHub under the MIT license. It is a 2-layer board measuring 45.1 × 48.5 mm, with 19 components from 6 distinct parts.
By type, the board carries 10 diodes, 4 resistors, 2 transistors, 2 capacitors and 1 connector.
From the project
- About the Project - Circuit Simulation - Schematic Design - PCB Design - Bill of Materials - Production Files - License - Contributing
- About the Project - Circuit Simulation - Schematic Design - PCB Design - Bill of Materials - Production Files - License - Contributing
The core of this project is an astable multivibrator built from two NPN transistors. The transistors alternately switch on and off: when one turns on, it pulls the other's base voltage low, preventing it from conducting. The capacitors charge and discharge through the resistors, creating a timing delay that causes the transistors to switch states repeatedly — making the LEDs blink back and forth like a siren.
TTL-SIREN bill of materials (BOM)
19 components, 6 distinct parts — part numbers from the project's BOM.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 2 | NPN | TO-92L_Inline_Wide | Q1, Q2 |
| 1 | CONN_01X02 Conn_01x02 | PinHeader_1x02_P2.54mm_Vertical | J1 |
| 10 | LED | LED_D5.0mm | D1, D2, D3, D4, D5, D6, D7, D8 +2 |
| 2 | 12U 12u | C_Disc_D5.0mm_W2.5mm_P5.00mm | C1, C2 |
| 2 | 330 | R_Axial_DIN0204_L3.6mm_D1.6mm_P7.62mm_Horizontal | R1, R4 |
| 2 | 1k | R_Axial_DIN0204_L3.6mm_D1.6mm_P7.62mm_Horizontal | R2, R3 |
TTL-SIREN design files
The KiCad project lives in the Gabouin/TTL-SIREN repository on GitHub; these links point at the commit this page was built from.
TTL-SIREN: common questions
How big is the TTL-SIREN PCB?
The TTL-SIREN measures 45.1 × 48.5 mm, has 2 copper layers and is 1.6 mm thick.
How many components are on the TTL-SIREN?
19 components, from 6 distinct parts, with part numbers taken from the project's own BOM. The full bill of materials is listed on this page.
Where can I download the TTL-SIREN design files?
From the Gabouin/TTL-SIREN repository on GitHub, which has the KiCad layout, the schematic and the BOM; the links under Design files point to each one.
Can I use the TTL-SIREN design in my own project?
Yes, under the terms of its MIT license, which Gabouin chose for the repository.