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Remote Telephone Ringer

Remote Telephone Ringer

This remote telephone bell ringer allows you to use a large and loud external bell in place or in addition to the built in ringer in most modern telephones. This is ideal for large outdoor areas, noisy shops or those hard of hearing. Most any large bell can be used as the circuit can be easily adjusted for various supply voltages.
Part Total Qty. Description

C1 1 0.47 300V Capacitor
C2 1 47uF 25V Electrolytic Capacitor
R1 1 1K 1/4W Resistor
R2 1 10K 1/4W Resistor
R3 1 1K Pot
R4 1 2K 1/4W Resistor
Q1 1 6A, 200V TRIAC
Q2 1 6A, 200V SCR (106, Etc.)
D1 1 1N4774 Zener Diode
D2, D3 2 1N4007 Rectifier Diode
U1 1 4N33 Opto Isolator
BELL 1 Large Bell (Fire Bell, School Bell, Etc.)
MISC 1 Board, Wire, Socket For U1, Case

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