Is this an over-voltage device?

How to keep the Cessna 170 flying and airworthy.

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Larry E
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Joined: Mon Sep 30, 2019 1:06 pm

Is this an over-voltage device?

Post by Larry E »

I'm hoping someone might be able to identify what this unit is:
What is this?
What is this?
The main positive output wire from the alternator goes to the left side terminal; and the right terminal wire then goes to the ammeter and main bus.
There is no identification on it - anywhere!
The aircraft came to Canada in 1974 and we don't have the American logs. There's no mention in the Canadian logs of the change from a generator.
Perhaps someone who's been around these old Cessnas for many years might remember seeing something like this.

Here is the voltage regulator;
Voltage regulator.jpeg
If it is an over-voltage device, does anyone know how they work?

Thanks in advance,
Larry
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n2582d
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Joined: Mon Apr 29, 2002 4:58 am

Re: Is this an over-voltage device?

Post by n2582d »

Larry,

That's a Radio Frequency Interference (RFI) filter. Here's one from Aircraft Spruce.
Gary
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c170b53
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Joined: Mon Apr 22, 2002 8:01 pm

Re: Is this an over-voltage device?

Post by c170b53 »

A quick glance, I would say thats a noise suppressor, removing any noise on the line.
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
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c170b53
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Re: Is this an over-voltage device?

Post by c170b53 »

Now I’m looking at the hole in my cowboy hat like Timothy Blake Nelson, in The Ballad of Buster Scruggs. You got the draw on me Gary!
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
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Larry E
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Re: Is this an over-voltage device?

Post by Larry E »

Gary and Jim
Thank youse!
I've not seen these before - are they needed? Or is it possible they were used as a band-aid to cover poor grounds, unshielded plugs and harness's or unwise cable routing, etc.?
There are also 2 magneto filters installed - one on each P-lead exiting the mags.
I'm wondering if all this was done in the 1960's, and perhaps not needed with modern avionics??
Larry
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c170b53
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Re: Is this an over-voltage device?

Post by c170b53 »

I rewired and installed one in my power feed years ago. Might be overkill or cheap insurance, I guess its up to the beholder.
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
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