Drive 9Vdc buzzer from 120Vac without using a transformer (no room)

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Thread Starter


Joined Dec 31, 2015

I have a protection circuit that needs to alarm when a fuse blows. The alarm needs to be a 9vdc 105db 8mA buzzer that is driven from a 120Vac power supply. I have no other load on this portion of the circuit. I do not have any room for a small transformer. Is this possible to do?? I have room for a full bridge rectifier to get my dc. How can I step down the voltage from 120 to 9 and for heat dispensing is it better to step down in ac or dc?
Thanks for any help.


Joined Apr 5, 2008

What you are asking is prohibited on this forum:

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