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Programmable Thermostat

Posted: Wed Mar 06, 2019 1:00 am
by Turkeytop
I thought that programmable thermostats wera a relatively recent development. We had our first one in the mid 90s.

There's a TV channel my wife watches that broadcasts old game shows. She had one on tonight that looked like 1970s vintage. One of the prizes was a thermostat that can set the temperature lower at night and back up in the morning. On the front plate it said "solid state." It had two rotary analog dials. Primitive by today's standards but they had them.

Re: Programmable Thermostat

Posted: Wed Mar 06, 2019 10:21 am
by SolarMax
"Solid state" meant/means an electronic device that uses transistors and diodes, a marketing term to indicate it had no old fashioned vacuum tubes. Don't recall any thermostat ever that contained vacuum tubes! The old thermostats had a springy bi-metal strip that flexed with temperature, activating a sealed mercury switch (tiny glass tube with a dab of mercury and a pair of contacts), to turn the furnace on or off.
The old "programmable" stats added simple mechanical timer switches, like those you can still get, that you plug a lamp into.

Posted: Thu Mar 07, 2019 8:42 am
by Arthur Mometer
There are some advantages to the "old" mechanical switches and timers, whether they are in your kitchen appliances, washing machines, dryers, and home irrigation equipment (AKA sprinkler timers). Oh. Thermostats. They don't have hundreds of PN junctions that can blow out in thunderstorms, high electrostatic atmospheric fields, power surges and failures, etc. All it takes is just one strategic junction to blow out and you are faced with a costly repair or replacement.

I had an old fashioned thermostat that had been used years ago, on a coal furnace. I studied the insides very carefully. My Dad and Mom were on a cleaning rampage. The last I knew, only the little Hg Column Thermometer still remained. It was in a metal cage where it was very unlikely to break. But it was as Mr. Clear Sky Sun Ray (thank you for deicing my driveway (and windshield) in the freezing cold weather, it was "sublime" :blink Solar power at its most efficient.) said.

The old thermostat was simple and complex at the same time. It had set screws to shorten or lengthen the heating cycle, one at the low temperature end, one at the high temperature end.

I had a mechanical Timex timer that got all messed up, but was easy to take apart and fix. Very logical.

Re: Programmable Thermostat

Posted: Sat Mar 09, 2019 8:46 am
by Deleted User 10525
When I had my HVAC unit replaced 4 years ago, I ended up with a programmable thermostat. I'm not a fan, every so often it's gets screwed up and stuck on some mode, where I have to take the battery's out and put them back in. The round one, I had that had a dial IMO worked just fine. Man do I sound like an old fart.

Re: Programmable Thermostat

Posted: Tue Mar 12, 2019 10:32 pm
by Turkeytop
SolarMax wrote:
Wed Mar 06, 2019 10:21 am
"Solid state" meant/means an electronic device that uses transistors and diodes, a marketing term to indicate it had no old fashioned vacuum tubes. Don't recall any thermostat ever that contained vacuum tubes! The old thermostats had a springy bi-metal strip that flexed with temperature, activating a sealed mercury switch (tiny glass tube with a dab of mercury and a pair of contacts), to turn the furnace on or off.
The old "programmable" stats added simple mechanical timer switches, like those you can still get, that you plug a lamp into.
Oh, I know all that. But back in those days, solid state was a term thrown out by marketing people to impress consumers. In the 80s "Digital " was the favourite marketing buzzword.

Notice how nowadays so many food products are advertised as "gluten free." Foods that wouldn't normally contain gluten are promoted as being gluten free, as if gluten free was healthier.

Re: Programmable Thermostat

Posted: Sat Mar 16, 2019 9:30 pm
by Ed Joseph
I honestly think the gluten is not the problem, the toxic chemicals in it ARE!

I have a "Smart" LOL thermostat. Every now and then, it decides to go into "auto" mode and tries to fire the AC up in the middle of winter.