Author Topic: variable capacitor across battery in digital indicator?  (Read 744 times)

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Online coppercone2Topic starter

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variable capacitor across battery in digital indicator?
« on: August 03, 2019, 07:21:06 pm »
What the hell is this shit, I have a dial indicator and it takes 2 batteries in parallel, it has two PCBs in it, the top PCB has the battery clips and a 3 pin connector to the main PCB. It has red black white wires, black is ground, red is diode dropped positive (rpp), white is a capacitive tap off the battery pos/neg. Yes a capactiive divider across a battery. then 1.5 inches of standard wire to the PCB. The thing is built like tank with a gasket and full aluminum body.

Why is there a air trimmer cap inside of a PCB that has two batteries , its value must be sub nanofarad.

All I can think of is some kind of noise balance thing? but it seems completely absurd.

Its a fancy trimmer cap thats fairly big, .4 inches diameter. It's literary like the type of capacitor you see in a old TV. Why do you need a variable noise tap off a lithium battery? Its fucking loctited too.

I am scared to touch anything now... is this something like a noise tap to start a oscillator?
« Last Edit: August 03, 2019, 07:25:34 pm by coppercone2 »
 

Online PA0PBZ

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Re: variable capacitor across battery in digital indicator?
« Reply #1 on: August 03, 2019, 07:34:01 pm »
Keyboard error: Press F1 to continue.
 

Online coppercone2Topic starter

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Re: variable capacitor across battery in digital indicator?
« Reply #2 on: August 03, 2019, 07:44:12 pm »
actually what was I thinking, capacitors don't work like that

its just connected to ground, confusing because the batteries are 2p1s and when you look at it, it looks like 2s1p

ok so its just a adjustable capacitive load going to the circuit. no big deal. thread can be deleted

there is some sharpie marks on the board that made the traces look weird (did not use flashlight)
« Last Edit: August 03, 2019, 07:46:09 pm by coppercone2 »
 


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