Questions tagged [thermostat]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
-2
votes
2answers
99 views

Is it safe to connect Neon indicating lamps with resistors to defrost timer and other fridge components? [closed]

I want to connect some indicative LEDs neon lights pulled from the switches of a multiple ways extension cord to the fridge. Initially the defrost timer, then later all parts and wires individually so ...
1
vote
2answers
147 views

Why is there a resistor in this circuit?

Why there is a 220 ohm resistor in this circuit? Can't we just connect the thermistor directly to the base of transistor?
0
votes
2answers
77 views

I don’t know what smart thermostat to use with my high voltage [closed]

I think I have 120v but not 100% sure, I don’t know what the wires do. I live in a condo with water cooling/heating furnace. Can someone help explain what the wiring means. Because I do not have a ...
0
votes
0answers
31 views

Can I get power from my Thermostat's AC relay wires?

I have a 2-wire thermostat that activates my baseboard heater when the 2 wires are shorted. I did an experiment closing those two wires with a relay and got that working well with an ESP32 as the ...
22
votes
8answers
6k views

Why do consumer ovens use thermostats instead of PID + PWM?

I measured the temp stability of my oven, and it's a really big swing of 10-15c in a saw tooth pattern. Aren't PI(D) controllers with variable output meant to dampen this type of oscillation? I ...
0
votes
1answer
150 views

Can W1209 be run with 5V DC only

I would like to control a small heat pad using W1209, using a power bank that provides 5V. My circuit is working if I connect step-up voltage controller to the power bank and increase its voltage ...
0
votes
0answers
32 views

Modified PWM for faster transient response

My heating controller "Thermostat" uses PWM of the water valve to control the heating power to the room. It has a fixed cycle length and varies the proportion of on-time to manage the ...
2
votes
0answers
61 views

Unknown symbol in thermostat schematic - two oblique lines inside a circle

Full diagram: What does the circle with two oblique lines inside it represent? It's an Emmeti Termec thermostat
2
votes
0answers
60 views

Will my 16 gauge wire eventually set my home on fire?

The fan relay draws 6.0A. That is a safe current for 16 gauge wire. The safety fuse is tripped at 15A which is too much 16 gauge wire. References: The below pdf link shows the Installation ...
1
vote
1answer
37 views

What's the Common and the NO in this diagram

I think the browns the common wire and the black is the normally open am I correct?
2
votes
2answers
81 views

Unconventional TEC peltier use (heating)

I'm going to be breeding reptiles, so I'll need an incubator. I'm currently thinking about using tec coolers as a heater inside an insulated box. The issue I'm thinking I'll have is that with a cheap ...
1
vote
1answer
43 views

two independent zones from central heating unit

I have a central heating unit (a pellet stove) for a two floor house. I'd like to control it independently from two thermostats. The stove at the moment is controlled by a single thermostat input and ...
1
vote
1answer
222 views

How to connect 15kΩ NTC thermistor sensor to thermostat which requires 10kΩ NTC thermistor

I have a electric floor heating in my house. Old DEVI thermostat broke down few day ago. Problem is that DEVI thermostats are expensive and a little bit dump (not smart). I want to replace thermostat ...
0
votes
2answers
584 views

Wiring in Thermostat (Rittal 31100) as a 24V Temperature Switch

I want to wire in the following thermostat. https://proax.ca/en/product/205417/RIT3110000 And am having a hard time understanding the wiring diagram I think I get that 5 is L and can be connected to ...
0
votes
3answers
233 views

How does the wired Tado smart thermostat operate without a neutral connection?

I’ve been studying the wiring diagrams for the Tado smart thermostat and noticed that it only uses a live ‘common’ and a switched live to operate. Given the smart thermostat has electronics which are, ...
0
votes
1answer
39 views

Heating element for Air Conditioner thermostat

I currently have a series of thermostats that are connected to a window air conditioner, one is used to check room temperature the other is to trick the AC to run to a lower temperature by switching ...
0
votes
1answer
27 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
1answer
63 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
200 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
45 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
0answers
26 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
2answers
132 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
59 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
1answer
69 views

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

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
89 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
2answers
5k 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
0answers
54 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
1answer
88 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
0answers
35 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
286 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 ...
2
votes
1answer
620 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
1answer
113 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
2answers
743 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 ...
1
vote
2answers
80 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
2answers
2k 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
1answer
239 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 ...
3
votes
1answer
132 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 ...
0
votes
3answers
218 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 ...
15
votes
6answers
5k 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
134 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 ...
0
votes
1answer
307 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 ...
2
votes
3answers
223 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 ...
0
votes
1answer
159 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
3answers
497 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 ...
1
vote
2answers
71 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 ...
2
votes
1answer
180 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 ...
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 - ...
1
vote
1answer
295 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. ...