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.
New Latching Levers for Circuit Checking Added to Our Best-selling MY General-purpose Relays
Power-switching Compact General-purpose Relays
Compact, Slim-profile SSRs with Heat Sinks. Solid State Contactors for Three-phase Heaters Reduced Installation Work with DIN Track Mounting.