I'm trying to trigger a relay using the piezo buzzer output of a countdown timer to put 12v across an external bell.
I have used the this relay driver circuit in the past to do a similar thing with a wireless door bell, but the doorbell receiver was 5v and I used the speaker output as the driving signal. The countdown timer is only using a 1.5v button battery.
I have used the this relay driver circuit in the past to do a similar thing with a wireless door bell, but the doorbell receiver was 5v and I used the speaker output as the driving signal. The countdown timer is only using a 1.5v button battery.