I need to build a surge suppressor to go on the input of an alarm
circuit. The circuit operates at 24.0 VDC. This is a two wire input
with an end of line resistor. I pulled an AC line toroid off an old
RCA TV and plan to connect it in series with my alarm circuit. Across
the other side of the toroid I plan to connect two 33.0 V MOV's in
series, with the center of the two connected to chassis, (building)
ground. This combination on the other side of the toroid will then be
connected to the alarm input. Additionally across the alarm input will
also be connected a 1.0 uf capacitor. My theory is: a transient first
sees the inductor which by nature resists a change in voltage. Next
come the series MOV's which should direct everything above 24.0 V
between each side of the line and ground, to ground. And finally will
be the cap which will hopefully take care of whatever is left. I know
that there are commercially available filters on the market but I
would really appreciate any thoughts on my idea. Thanks, Lenny

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| l
M l
Line |,,,,, __l__ To alarm panel input
in | | ____
M GND l
| l
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