I am making a RIAA preamp, opamp based. I'm going to power it from two 9V batteries, but I would like to have the preamp switched on when I power on the record player. The record player uses 120V AC to power the motor.
I'm going to switch the preamp on with a 5V relay that needs 25mA to activate. Because I need so little power for the relay, I would like to not introduce a AC-DC transformer/rectifier into the equation. Is it possible I can 'steal' enough current from the AC power cord by induction, when the unit is powered on?
Or maybe I should just use an AC powered relay?
I'm going to switch the preamp on with a 5V relay that needs 25mA to activate. Because I need so little power for the relay, I would like to not introduce a AC-DC transformer/rectifier into the equation. Is it possible I can 'steal' enough current from the AC power cord by induction, when the unit is powered on?
Or maybe I should just use an AC powered relay?
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.