Questions tagged [thermostat]

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14
votes
6answers
4k views

What is the reason for a fuse next to a thermostat?

I'm repairing a heater that someone threw in the trash (this model): It has an internal thermostat next to the heating wires, plus a thermal fuse. What is the reason for a fuse in addition to the ...
3
votes
1answer
113 views

What could be this particular thermometer used for?

I came across this rather strange looking thermometer. It seems to have two scales and some kind of wires inside it. There are two terminals at the top. Is it a thermostat? But it seems to be too ...
3
votes
2answers
2k views

Switching a millivolt gas valve with a low-voltage digital timer

I have one of those old gas heaters that has a millivolt valve powered by a thermopile. I want to control it with the brain of a digital programmable outlet timer (minus the AC switching components - ...
2
votes
3answers
195 views

heating element for miniature working oven

Please don't laugh but I am building a small working oven for my daughter and need a heating element that can heat it from 70 to 220 degrees celsius via a thermostat. I've found this heating element ...
2
votes
1answer
162 views

Using AC relay with DC voltage

I apologise in advance if this is the wrong forum, or I'm not providing enough details. I'm building a thermostat zone controller on a raspberry pi and I've encountered an issue with the relays in my ...
1
vote
2answers
70 views

Can I permently connect the resistant of a coffee machine [closed]

I have a simple coffee machine that has a little "controller" that control the ON/OFF of the heater. Suddenly, the machine stop heating the water (and the recipient). I have open the base and test ...
1
vote
2answers
72 views

External fan to come on when AC unit comes on.

I want to have an additional 120v fan come on when the AC unit is on. Am I able to wire that off the thermostat somehow?
1
vote
1answer
262 views

What kind of load do US thermostat control signals drive?

This page has some really good information on heating system wiring in America. One thing I can't tell from it though, is what exactly the 24VAC call-for-heat and call-for-cool signals drive. ...
1
vote
1answer
220 views

What kind of relay should be used to control a thermostat terminal?

I'm building a remote controller for my thermostat, and the only step I have remaining is the connection between the Raspberry Pi and the thermostat terminal. Essentially, the Rpi will be replacing my ...
1
vote
2answers
1k views

Can I take DC directly from W1209 Thermostat board?

I want to make an incubator. So I am using W1209 thermostat. I want to control AC and DC. I can control AC (220v AC) by the relay output. Can I control DC by connecting DC directly from the relay ...
0
votes
3answers
182 views

“Sniffing” into a Boiler's LED panel (Central Heating)

I've built an esp8266 based web thermostat to control my heating system. Everything seems to be working fine for the moment :) What I want to accomplish is "sniff" or intercept the boiler´s status ...
0
votes
2answers
34 views

Regulating precision heating

Whats the simplest electr(on)ic(al) method for heating a coil or similar element to a specific temperature? Generating heat is easy; dictating and regulating a specific temperature is the hard part. ...
0
votes
2answers
44 views

Need help understanding details of thermostat wiring scheme

I bought this thermostat to control air circulation, that is using it for cooling purpose. So far I managed to make it work, but I do not fully understand the wiring scheme. I would appreciate help to ...
0
votes
1answer
50 views

Are conventional fridge thermostats active or passive?

I am talking about specifically this thermostat used in cooling systems My query to engineers & technicians is that: Can we check the working of above thermostat with only continuity tester and ...
0
votes
1answer
101 views

Debugging an old Thermostat: What component is this? (3 pins SMD IC)

My Thermostat stopped working a couple of days ago and I tried to debug it. The first thing I check is if there is any component that gives a strange result with the multimeter and I found these ...
0
votes
2answers
748 views

Wiring Nest Thermostat E Heatlink in place of original Thermostat

I have a Nest Thermostat E, which requires me to replace my thermostat with the Nest Heatlink. Google provides step by step instructions on how to do this using a series of questions and answers. ...
0
votes
2answers
503 views

Relay or optocoupler to switch thermostat wires

I'm doing a project to replace my thermostat with a DIY one. I'm trying to figure out how to switch the heating/cooling/fan/humidity wires. I'm inclined to go with an optocoupler like the 4N35. It ...
0
votes
1answer
67 views

Insert Arduino into Thermostat circuit, but no common

I thought I was all ready to replace a thermostat with an Arduino. I used a multi-meter and bridged some connections to discover the following: 1. bridging 230V (live) with Cool turns on the Aircon ...
0
votes
1answer
87 views

Thermostats outputs to GPIO then to Furnace

I have a question on how to safely connect and detect Thermostats outputs to Controller's GPIO inputs (RasPi and BeagleBone). I've been looking up a lot and most of the cases it is showing me how to ...
0
votes
1answer
213 views

Bimetallic Thermostat

I have a One Shot Type Thermostat CS-7TA-35 195 6103 that i've removed from a laser printer's fuser unit. There was a paper jam within the fuser unit which I assume tripped this "one shot" by metalic ...
0
votes
1answer
134 views

Integrating MAX31855 with FPGA to make thermostat

NOTE: I am newish to FPGA programming. I have only taken 1 university course for it. I am looking for direction on where to start, not for someone to do it for me. I bought a MAX31855 k-type ...
0
votes
1answer
25 views

Advice on setting up sensor switch

Hi I would like to fit a (motion sensor/IR sensor) sensor switch to a machine in my catering van. The machine is a 12v machine. I would like to start the machine using the sensor switch and would like ...
0
votes
0answers
21 views

Bi-stable switch activated in both directions by a momentary electrical input

I am trying to find or build an electro-mechanical "switch" for a unique application. It should act a little bit like the snap switch used in thermostats (where a bi-metal disk snaps from concave to ...
0
votes
1answer
57 views

Temperature Sensing and board heat

My goal is to have an accurate measurement of the current temperature in my room, which I will use for a thermostat. The problem I have is I bought this breakout board and soldered it to about 5cm ...
0
votes
0answers
27 views

Nest thermostats wiring problem 3 storey house (3rd gen, E, analogue one)

My house has 3 storeys and 3 thermostats. 2nd and 3rd floor have nest e and nest thermostats respectively. The 1st floor has an old analogue one that used to work ok. After the nest upgrade I noticed ...
0
votes
0answers
43 views

Reed switch passive interupt for garage heater when door is open (using NC switch)?

I'm trying to prevent my garage heater from running while the garage door is open to prevent it from attempting to heat the entire neighborhood if/when the door is accidentally left open. I have a ...
0
votes
0answers
31 views

meanwell psu inrush current and temperature sensor

I want to use a Meanwell PCB mounted power supply on my next project. https://www.meanwell.com/Upload/PDF/IRM-20/IRM-20-SPEC.PDF The spec sheet says that it has an inrush current of 20A/115VAC (I'm ...
0
votes
0answers
30 views

4 Wire Thermostat for Two Separate Heaters

Is there any reason why I cannot use a 4 wire thermostat (Honeywell T410B, DPST) to control two separate heaters (they are fairly close to each other)? The contacts are each(?) rated for 22 A and let'...
0
votes
1answer
147 views

Can I simply add a 240V Neutral to SONOFF TH10 when replacing wall thermostat

So, I have purchased a SONOFF TH10 wanting to use it to replace my wall mounted thermostat. The thermostat has 2 connections: Always-Live and Switched-Live (which is activated of course by the ...
0
votes
0answers
44 views

Compact way to fake a 24VAC relay?

I am integrating a Nest Thermostat with an open automation software, and need to make it think its W, Y and G wires are connected to something -- normally a 24VAC relay driving 120V appliances. How ...
0
votes
1answer
180 views

Replace copper capillary thermostat with digital temperature controller relay

Our lab has an old New Brunswick Model G25 incubator shaker. Its temperature control function is broken lately. We would like to replace the two copper capillary thermostats with modern digital ...
0
votes
3answers
367 views

Question about thermostat circuit

Can anyone clarify if I am not understanding this comparator circuit correctly. The author says that if the temperature drops across the ntc thermister, resistance will go up and cause output to go ...
-3
votes
1answer
119 views

HVAC heating control with thermostat, on/off or continuous? [closed]

I have a honeywell rth8580wf heating thermostat. I wonder what the output of the "white" terminal is (heating control). Is it only going from 0V to 24V or is it continuous depending on the room ...