Canister Light Question

mml

Newly Enlightened
Joined
May 10, 2020
Messages
1
Hello,

I have a dual piezo EO cap.
Both switches stopped working. I found a problem with the capacitor inside the cap.
There are 2 separate circuit boards, however, one of the boards has a capacitor across the red and black terminals, the other one does not.
I removed the capacitor and both switches work again.
How important is the capacitor. Why would it only be on one board and not both.
I can't post any attachments yet, so hopefully the above description will help.
 

lightfooted

Flashlight Enthusiast
Joined
May 6, 2010
Messages
1,017
Hello,

I have a dual piezo EO cap.
Both switches stopped working. I found a problem with the capacitor inside the cap.
There are 2 separate circuit boards, however, one of the boards has a capacitor across the red and black terminals, the other one does not.
I removed the capacitor and both switches work again.
How important is the capacitor. Why would it only be on one board and not both.
I can't post any attachments yet, so hopefully the above description will help.

Debouncing most likely. To prevent multiple "presses" of the button being detected from a single actual press. As to the "why" ...well it was probably the way the circuit was designed. One side may need it while the other is better filtered inside the driver chip or whatever is being used to control it. Is it necessary? Probably. I really doubt it would have been on the board if it wasn't needed. Maybe it won't be a problem right away or maybe you will never see the problem it creates.
 
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