Relay (SRD-12VDC)
SPDT power relay · 12 V coil (400 Ω, 400 mH) · contacts 10 A 250 V AC · pulls in at 70 %, drops out below 25 % of coil current
Try it on the benchThe lab drops it on an empty bench and opens its datasheet card.
Typical part: Songle SRD-12VDC-SL-C
Pins
- Coil +
- Coil −
- COM
- NO (normally open)
- NC (normally closed)
Ratings and limits
| Coil | 12 V, ≈ 400 Ω |
|---|---|
| Contacts | 10 A 250 V AC / 10 A 30 V DC |
| Pull-in / drop-out | ≥ 75 % / ≤ 10 % of coil voltage |
How to use it
Switch mains or heavy DC loads from a transistor. Always put a diode across the coil.
Lessons and builds that use it
- Inductive load and the flyback diode
- Light-activated switch with relay
- Automatic emergency light (build)
- 555 delay-off timer with relay (build)
- 10. Relay: switching a real lamp (build)
- 11. PIR sensor: only when someone is there (build)
- 12. 555 timer: stay on after they pass (build)
- 13. Buzzer: an alarm mode (build)
- 14. Solar: the light runs off-grid (build)
- Home UPS on a 24 V LiFePO4 battery: charger, inverter, changeover relays, two 220 V outputs (build)
- Home UPS on 8 × 3.2 V LiFePO4 cells + BMS: charger, inverter, changeover relays, two 220 V outputs (build)