Page top

page-top

Omron uses cookies to improve your experience on this website. By continuing to use the website, you hereby agree to our Privacy and Cookie Policy

Lead Contents

Humming of Solid-state Relay

FAQ No. FAQ02079

Primary Contents

Question

Why do Solid-state Relay load Relays sometimes hum?

Answer

Leakage current flows when the Solid-state Relay input is OFF. If a small Relay is driven, this Leakage current may cause the Relay coil to become slightly energized, which results in a humming sound being produced.

Insert bleeder resistance in parallel with the Relay coil to eliminate any humming. The same effect as bleeder resistance can also be obtained by connecting multiple Relay coils in parallel or connecting the Relay coil in parallel with another load.