Inside an isolated relay.
How can a tiny control circuit switch a separate load?
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How can a tiny control circuit switch a separate load?
Fit the relay and apply control power
Coil current attracts the armature against its spring. The moving contact closes an electrically isolated load circuit; load current does not pass through the coil.
A simplified non-latching relay with a 35 mA pull-in threshold and a 48 Ω load. Coil and load have isolated circuits; mechanical hysteresis and contact arcing are omitted.
Close the load contacts with no electrical connection between control and load.
Switch the isolated load circuit using coil power.