The International Cessna^® 170 Association

Hi all,

The 20 amp generator and voltage regulator died in my 170B. I had the generator replaced, but my AME couldn't find or source a suitable 20 amp regulator. For the time being, I'm using a loaner 35 amp regulator.

Any idea where I can find one?

Thanks in advance,

- 1955 170B

I have a 20a that you can have. I can post or come and get it.

I changed to Zeftronics. Gave a charge at lower rpm and less bouncing of the ammeter.

daedaluscan wrote:I have a 20a that you can have. I can post or come and get it.

I changed to Zeftronics. Gave a charge at lower rpm and less bouncing of the ammeter.

I'd appreciate that! I'd love to pick it up from you if you don't mind.

Is the Zeftronics just a swap in regulator which allows you to charge at a lower rpm, or does it require modification to the generator too? Maybe long term I can consider this.

Sure anytime. Im at the hangar most afternoons. Text 250 818 8727 to be sure.

Zeftronics is a solid state solution. Straight swap.

A 35 Amp regulator controlling a 20 Amp generator will DESTROY THAT GENERATOR. The 35A reg will request more output than the 20A gen can produce and the gen will overheat and fail.

Either obtain a salvage replacement, an automotive replacement, or the Zeftronics unit, IMO. (Advisory Circular AC 23-27 may provide your A&P with the necessary approval basis for an automotive part.)

See this post: viewtopic.php?f=24&t=3437&p=28530&hilit ... tor#p28530

GAHorn wrote:A 35 Amp regulator controlling a 20 Amp generator will DESTROY THAT GENERATOR. The 35A reg will request more output than the 20A gen can produce and the gen will overheat and fail.

Either obtain a salvage replacement, an automotive replacement, or the Zeftronics unit, IMO. (Advisory Circular AC 23-27 may provide your A&P with the necessary approval basis for an automotive part.)

See this post: viewtopic.php?f=24&t=3437&p=28530&hilit ... tor#p28530

Interesting! I have a brand new generator, and I certainly don't want to wreck it again. My AME told me to replace it with this one, which I did. Standard Motor Products VR22 https://www.amazon.ca/Standard-Motor-Pr ... 184&sr=8-1. I believe it's 35 amp?? It's an automotive one. Now I'm worried...

I'm going to take Charlie up on using his regulator once I'm able to pick it up. Hopefully it's alright to limp mine for the meantime.

George is correct. There is no way really to just limp along cause you have no way to tell or restrict this regulator from calling for 35 amps from your generator, which it can't supply. I suppose you could monitor your amp meter and shut off the master switch if the load exceeds 20 amps. Not a plan I'd go with for very long.

The question is, how long your generator will survive under a 35 amp call. I'm sure if we'd asked this question in the 50s or 60s the expertise available at the time could have told us. That is long gone. However I'd doubt the generator would immediately burn up. I still wouldn't run your generator that way.

Your BEST solution will be to purchase the Zeftronics G1200N regulator. Spruce sells it and it’ a direct solid-state replacement: https://www.aircraftspruce.com/catalog/ ... g1200n.php

GAHorn wrote:Your BEST solution will be to purchase the Zeftronics G1200N regulator. Spruce sells it and it’ a direct solid-state replacement: https://www.aircraftspruce.com/catalog/ ... g1200n.php

Wow, this site is such a valuable tool. I called around 3 different AME shops and no one knew where to find the appropriate regulator for my generator and airplane configuration.

Charlie is kindly giving me his old regulator so I'm going to install that for now. If I have problems in the future, I'll upgrade to the Zeftronics one.

reecewallace wrote:

GAHorn wrote:Your BEST solution will be to purchase the Zeftronics G1200N regulator. Spruce sells it and it’ a direct solid-state replacement: https://www.aircraftspruce.com/catalog/ ... g1200n.php

Wow, this site is such a valuable tool. I called around 3 different AME shops and no one knew where to find the appropriate regulator for my generator and airplane configuration.

Charlie is kindly giving me his old regulator so I'm going to install that for now. If I have problems in the future, I'll upgrade to the Zeftronics one.

Good decision! (And the Zeftronics model will make the generator behave more like an alternator, as it brings the gen on-line at lower RPM according to the designer. I’ve met Femi Ibitayo and he is an electrical engineering graduate of Le Tourneau Univ in Longview and established his company to send a portion of their profits to western Africa to support Christian businesses and families, who often are threatened with violence by others as “infidels”. Although I don’t consider myself devout, I was very impressed with him, and his small shop.)