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DiscoverCircuits.com
-- Hobby Corner
Last Updated on:
03/19/2008 06:54:11 AM |
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Basement Front Doorbell Beeper |
| If you can’t hear your front doorbell when you are in your basement, this
circuit might work for you. Whenever the front doorbell button is pressed, the hobby circuit will activate a loud beeper positioned in
the basement. This circuit takes advantage of the fact that in many homes, the 24vac power transformer used to power the doorbell is located
near the furnace in the basement. A box containing the electronic circuit could be mounted next to the transformer. |
| A small bridge rectifier converts the 24vac into DC. The 100uF capacitor
filters the pulsating DC from the bridge to form about 30v DC. Three diodes are wired in series with the door chime. Whenever the
front door pushbutton is pressed, the door chime sounds. AC current drawn b the chime is routed through the three diodes shown.
The two diodes in series forms a 2 volt voltage source, which is connected to an inexpensive opto-isolator. The 2 volts across the two
diodes is sufficient to turn on the opto-isolator circuit, which routes DC to the gate of the ZVN4206 FET. When the doorbell chime
sounds, the FET turns on a piezoelectric beeper, drawing power from the 30 DC supply. Make sure the beeper you use can handle the higher
30v voltage. |
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Click on Drawing to view PDF |
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