Can I drive a relay with a transistor?

ID: FAQE10040E



DC coil relays can be driven by transistors.
However, the back electromotive force generated by the coil when it’s turned off may cause damage to the semiconductor or device malfunction. As a countermeasure, add a surge-absorbing circuit to both ends of the coil.


For more about protecting relay coils from surge, refer to FAQE10041“What are surge countermeasures in coil relays?” and Safty Precautions for All Relays: 2-2-5 Preventing Surges When the Coil Is Turned OFF.

Quick tips

If a surge-absorbing circuit is added, the relay release time will be longer. Check the circuit before use.

Product category Relays Signal Relays Power Relays
Classification Usage, Applications
Related keywords
  • Signal Relays
  • Power Relays
  • Transistor Drive
  • Back Electromotive Force
  • Surge-Absorbing Circuit

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