

| Subject: | Re: Some dometic notes |
| From: | Neil N |
| Date: | Mon, 1 Jul 2019 10:28:26 -0700 |
Thank you for taking time to write that information David. I now better understand the parts involved. Kind of moot for me as I gave up on Dometic 182 fridges some years ago but I really liked the LP aspect them. We all know how a compressor style fridge can increase project costs (batteries, etc) Neil. On 7/1/19, David Beierl <dbeierl@gmail.com> wrote: > The thermocouple output is proportional to temp difference between the two > junctions. But the output is either enough to hold the gas valve open, or > not. Certainly an eroded one is on the way to failure. > ..... The > thermocouple is basically two pieces of wire, so it has ridiculously low > impedance. That means that its tens of millivolts output can push IIRC > better than one ampere through the magnet in the gas valve, which is only a > few turns of heavy wire with pole pieces that are machined flat. The > actuator piece is also machined very flat, so that it makes extremely good > physical contact with the pole pieces. Because of the close contact the > magnetic circuit is very good and the valve can be held open with > considerable force. But that force vanishes as soon as the two pieces > break contact, so the valve has to be opened by you "pushing the pickle". > > >> > > The thermostat is a snap-action device operated by that capillary tube. > When it calls for cooling, it opens a clear channel for gas to pass through > and be limited by the orifice. When it does not, the gas for the pilot > flame is metered through an extremely small orifice inside the gas valve. > The flame has only two levels; cooling and pilot. -- Neil n VE7TBN 1988 Westy 50º ABA swap: https://tinyurl.com/yap5hpwt 1981 Westy 15º ABA swap: https://tinyurl.com/y9n4xob8 VAG Gas Engine Swap Group <http://tinyurl.com/khalbay>
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