4 ms·
As a kid we had a very simple (mercury) thermostat which had two levers -- one for heating set-point & one for cooling set-point. I recall it working quite wel
by adanto6840 4y ago
As a kid we had a very simple (mercury) thermostat which had two levers -- one for heating set-point & one for cooling set-point. I recall it working quite well.
- beambot 4y agoAlways thought the old mechanical bimetallic strip solution was particularly elegant. In effect, two strips of metal were bonded together forming a coiled "spring." Because each metal had different coefficient of thermal expansion, the spring would expand or contract to different lengths depending on the temperature. Place the electrical contact at the temp where the heater or HVAC should turn on & bam. No electronics at all, just a temperature-dependent mechanical switch.
- AlbertCory 4y agoExactly. I had a problem with the temperature in my house often being wrong, so I bought a smart thermostat. Now I have ten problems.
- rootw0rm 4y agothey still exist, that's what cheapo thermostats still use. i've wired up a couple thermostat controlled extension cords over the past couple years for a dog house and chicken coop using them
- KMag 4y agoAlso, they usually had a tiny magnet at the tip of the bimetallic strip to make their decisions path-dependent (more "sticky"/less flip-flopping).