Transducer for Comfortron Part I

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Doc Hubler
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Transducer for Comfortron Part I

Postby Doc Hubler » Thu Nov 13, 2014 8:31 pm

I posted this on the FB site earlier. Thought there might be some here that were interested, or know more about this than I do. Here are some pictures of the transducer unit for Comfortron Automatic Climate Control in the Toronado (same at least for 66-68). The unit is mounted on the firewall passenger side (interior, just below glovebox). These units convert voltage to vacuum. The vacuum controls the lever on the Power Servo mounted on the air handling box in engine compartment. Essentially, input from the control unit on the dash and the 3 temperature sensors in the car give a particular voltage. The particular voltage running through the very thin wire causes the wire to contract to differing amounts causing no vacuum bleed off or some vacuum bleed which causes the power servo arm to position in 3 basic steps, thus operating a different set of vacuum valves to open (a stator moves position with the servo arm). Anyway, the transducer is simple really in design. The issue with these is the vacuum diaphram in most cases I think. mine had a small hole in it so it didn't work. I tore it apart and here are the pieces. If there were a way to make the special diaphram, these could be repaired. The FSM just says to replace the unit if it fails -- there was not repair kit for these. Read the picture annotations if you want more info.

Transducer 1.jpg
Transducer 1.jpg (74.31 KiB) Viewed 16016 times

Transducer taken apart. The vaccum end is clearly evident. It is held on with two screws. You have to loosen the electrical end so the wire loop can move the direction to be careful when disasembly occurs to not break the thin wire. For the vacuum end, there is a brass fitting with an o-ring to seal it to the small vacuum tube end. The little copper ring (castle ring) is pushed into place to hold the brass/o-ring piece tight agains housing. The other parts above teh wire loop are all parts of the diaphram spring assembly. The end wire is bent a little, but it goes through the hole in the previous mentioned brass fitting. The wire loop is held by a metal piece that fits in the diaphram and allows air to bleed through to reduce vacuum. As the wire contracts when voltage is applied, it pulls the diaphram spring forward, sealing the diaphram and the power servo arm gets full vacuum. When the wire is relaxed and there is little or no voltage applied, the diaphram spring relaxes and seals the small bleed hold in the diaphram. The power servo arm gets reduced vacuum and moves to a different position.

Transducer 2.jpg
Transducer 2.jpg (72.48 KiB) Viewed 16016 times


The wire of the transducer. Looks like a bimetallic setup -- different conductivity of different metals. You can see the metal piece that catches the wire loop at the top right. This piece also fits into the top of the diaphram unit opposite the spring side. When the wire contracts, it pulls the diaphram towards the wire loop sealing off the bleed valve. When there is little or no voltage across the wire, it relaxes and the bleed valve opens thus causing reduced vacuum to the power servo arm and causing that to move and the stator as well.

Mikel
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Re: Transducer for Comfortron Part I

Postby Mikel » Sat Aug 13, 2016 5:20 pm

Bringing this back from the dead - These days it is very inexpensive to 3D print parts. There are rubber materials available too.
I'm in the middle of resurrecting my Comfortron too. If someone wants to send me their broken transducer diaphragm, I can create a 3D model on CAD and we can see about having parts made.

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Doc Hubler
Posts: 363
Joined: Thu Sep 27, 2012 9:37 pm
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Re: Transducer for Comfortron Part I

Postby Doc Hubler » Sun Aug 14, 2016 5:07 pm

Mikel,

Would be happy to send you this one. I found what might be the last three NOS transducers, and purchased them. I'm installing one in my car. Eventually, they'll all wear out. So would be good to have parts.

Mikel
Posts: 134
Joined: Tue Aug 11, 2009 7:26 am
TOA Membership Number: 100
Location: New Haven, CT

Re: Transducer for Comfortron Part I

Postby Mikel » Tue Aug 16, 2016 6:19 am

Doc Hubler wrote:Mikel,

Would be happy to send you this one. I found what might be the last three NOS transducers, and purchased them. I'm installing one in my car. Eventually, they'll all wear out. So would be good to have parts.


Hello Doc,
I sent you a message.

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Doc Hubler
Posts: 363
Joined: Thu Sep 27, 2012 9:37 pm
TOA Membership Number: 992
Years Owned: 1967

Re: Transducer for Comfortron Part I

Postby Doc Hubler » Tue Aug 16, 2016 10:44 am

Hi Mikel!

I did get a message on my regular email, and responded to it, but haven't seen any other messages here or on email. Can you just use the board on this site? I'll try to respond there.

Mikel
Posts: 134
Joined: Tue Aug 11, 2009 7:26 am
TOA Membership Number: 100
Location: New Haven, CT

Re: Transducer for Comfortron Part I

Postby Mikel » Tue Aug 16, 2016 11:18 am

Doc Hubler wrote:Hi Mikel!

I did get a message on my regular email, and responded to it, but haven't seen any other messages here or on email. Can you just use the board on this site? I'll try to respond there.


Hi Doc,
Since I never got your response, could you please paste it here?
Thanks.

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Doc Hubler
Posts: 363
Joined: Thu Sep 27, 2012 9:37 pm
TOA Membership Number: 992
Years Owned: 1967

Re: Transducer for Comfortron Part I

Postby Doc Hubler » Sun Sep 18, 2016 9:43 pm

What are you looking for? Mikel is working from the transducer I sent him. I hope he might have some luck with it. He's trying to make a new diaphram. The key part.

Mikel
Posts: 134
Joined: Tue Aug 11, 2009 7:26 am
TOA Membership Number: 100
Location: New Haven, CT

Re: Transducer for Comfortron Part I

Postby Mikel » Fri Mar 23, 2018 4:37 pm

Looks like these guys overhaul comfortron components. I'm going to send them my transducer.

https://originalair.com/restoration-gm-controls


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