Solid State Relay
Build a solid-state relay (SSR) using BT136 TRIAC. Controls AC loads without mechanical contacts, ideal for DIY electronics, automation, and hobby projects.
SSR circuit using TRIAC:
BT136 is a solid-state relay that can control AC loads without any noise. The BT136 TRIAC is a low-voltage DC input DC switch with low voltage and high reliability, fast and reliable operation.
DIY SSR for electronics:
The Solid State Relay (SSR) based on BT136 is an electrical switching device based on an AC load that does not use any mechanical connection. In contrast to mechanical relays, it makes use of a TRIAC (BT136) operated by a low-voltage DC control signal, which is silent, fast, and long-lasting to switch. It is a project that is suitable for hobbyists, students, and those who enjoy DIY electronics who seek reliable AC load control. The opto-isolator or resistor-diode triggering circuit is triggered by the input control voltage and switches the BT136 TRIAC ON or OFF, as performed by the AC load. SSRs can be used with lamps, small motors, heaters, and other AC appliances, providing better control and operational life than conventional relays. The design is focused on safety, effectiveness, and compactness, and it is ideal in an educational setup, home automation, or small-scale industrial applications.
⚡ Work & Installation (Input → Output):
- DC Control Input → Low-voltage DC triggers the SSR.
- Opto-isolator / Trigger Circuit → Activates BT136 gate safely.
- BT136 TRIAC → Switches AC load ON or OFF.
- AC Load → Lamps, motors, heaters, or other AC devices.
- Installation → Assemble components on PCB or breadboard. Connect AC load to TRIAC terminals, and DC control to gate circuit. Test SSR switching with low-voltage DC input.
Testing & Final Adjustments:
Connect the DC control input after assembly and make sure that the AC load switches ON and OFF. Check the gate triggering using a small current to make sure that it works. Be sure that the AC load and control circuit are isolated to avoid electric shock. Modulate the values of resistors and diodes in the triggering circuit to maximise the TRIAC switch. Test several AC loads to ensure the reliability of the SSR and note silent switching. Safe and consistent as well as efficient AC load control can only be guaranteed through proper testing, and thus, the BT136 solid-state relay is ideal in DIY electronics, home automation, and hobby applications.
