I want a temperature controller for a 12V, 40W ceramic cartridge heater

[BhargavRJ]

TL;DR Summary

I want a temperature controller for 12V, 40W ceramic cartridge heater. Can I use regular market temperature controllers which have Relay output?

Dear friends, I am in a search of a temperature controller for 12V, 40W ceramic cartridge heater! I can not change the heater because of my application. I want to purchase a simple PID temperature controller available in the market. But I am not sure whether they can provide me the 12V output. And I also don't know which relay I should connect. Again that relay should be cheap. Can I use simple 12V relay which we use with arduino with such temperature controllers? Please help me with this. I am irritated because, I am not able to find anyone who has used 12V heater with temperature controllers of such. I am talking about these kind of temperature controllers.

Please find more details about such temperature controllers on below link:

[Link removed by the Mentors]

Please forgive me for my english.

Thanks

 

[berkeman]

Summary:: I want a temperature controller for 12V, 40W ceramic cartridge heater. Can I use regular market temperature controllers which have Relay output?

Dear friends, I am in a search of a temperature controller for 12V, 40W ceramic cartridge heater! I can not change the heater because of my application. I want to purchase a simple PID temperature controller available in the market. But I am not sure whether they can provide me the 12V output. And I also don't know which relay I should connect. Again that relay should be cheap. Can I use simple 12V relay which we use with arduino with such temperature controllers? Please help me with this. I am irritated because, I am not able to find anyone who has used 12V heater with temperature controllers of such. I am talking about these kind of temperature controllers.

Please find more details about such temperature controllers on below link:

[Link removed by the Mentors]

Please forgive me for my english.

Thanks

View attachment 268252

Welcome to the PF.

What are you going to be heating? How are you sensing the temperature (with a thermocouple?)? What temperature accuracy are you wanting to maintain?

What will be the life of this setup? If you want years and years, you may want to use a solid state relay instead of a mechanical one. Mechanical relays have a limited lifetime, depending on the inrush current into the heating element.

https://www.matterhackers.com/store...dJ81ItLQ1EUOQ26UgBtg3r-EteLmZcOxoCgJsQAvD_BwE

 

[BhargavRJ]

I want to make a small hotplate. It's okay for short life time because I am trying this for a first time. I will drill a hole in small aluminium block and try to heat it. 1° accuracy will be okay for my project. I am having same heater provided in the link above and I want to have a temperature controller for it.

Any help will be appreciated a lot.

 

[jrmichler]

Your 12 V 40 W cartridge heater draws 40/12 = 3.3 amps. You need to provide a 12V power supply rated for a little more than 3.3 amps. The heater works exactly the same with either AC or DC power. A good choice would be a 12 volt transformer rated at 5 amps.

The temperature controller has a relay output rated 230 volts and 5 amps. Since your heater needs only 12 volts and 3.3 amps, the internal relay in the temperature controller should work nicely. Just connect the transformer to the temperature controller relay to the cartridge heater.

This temperature controller has two relay outputs. Make sure you connect to the correct relay. The other one is rated for only 50 ma (0.05 amps), so would be destroyed if you tried to use it.

Make sure that your temperature sensor is close to the heater. If it's too far away, control will be poor because the temperature will oscillate between too low and too high. I suggest inserting the temperature sensor in a hole about 2 or 3 mm from the hole for the cartridge heater.

 

[BhargavRJ]

Thanks a lot. You cleared out my all the doubts. I will assemble these things now, and let you know how it is working. Again, Thank you very much.

 

[DAVIIDD]

I have similar questions to yours and was wondering if I could get the schematics of your design for the ceramic cartridege.
Is it working? or are there any improvments to be made?
Any kind of information would be helpful,
Thx in advance

 

[BhargavRJ]

Yes, It is working. For that you will require one temperature controller, one SSR and an Transformer(as per your cartridge heater - For 12V cartridge heater a step down transformer of 12V with 5Amps current rating will be sufficient). Wiring is pretty simple.

 

[DAVIIDD]

Is Step down transformer something like this in the picture?

 

[berkeman]

View attachment 297441Is Step down transformer something like this in the picture?

That definitely does not look like a step-down transformer. It looks like a switching power supply of some kind.

 

[hutchphd]

For those who like to reuse everything may I promote the use of switching power supplies from desktop computers, particularly those that were past their prime a decade ago. They supply 5V and +/_12V and usually 3.3V at very happy amperage. You need only to rig the power made good (to ground as I recall) and provide a small idling load to keep it switching if necessary. Lotsa amps cheap. One runs my lab overhead LEDs and provides big amps at 5V when I need it. They are not hard to find.
When I need finesse I have my HP supply.

 

[berkeman]

and provide a small idling load to keep it switching if necessary.

Folks should be sure to check the datasheet for this type of PSU that they want to use. In my experience, the minimum output current (at least on the main rail) is not a small fraction of the rated load. That's one way that the designers have been able to cost-optimize the PC power supply designs (wider output load current ranges are harder to support).

 

[hutchphd]

In my experience, the minimum output current (at least on the main rail) is not a small fraction of the rated load.

Very good point and I do remember being surprised by that. But of course my choices were largely dependent upon the carcasses on my shelf, and it worked out fine. As I recall the idle currents were tens of mA (or more?)...but my applications don't require standby power so I just power them up as necessary. Like this heater application presumably.

 

[DAVIIDD]

Yes, It is working. For that you will require one temperature controller, one SSR and an Transformer(as per your cartridge heater - For 12V cartridge heater a step down transformer of 12V with 5Amps current rating will be sufficient). Wiring is pretty simple.

Could you tell the step down transformer that you bought?
That would be really helpful.

 

[hutchphd]

Also just for the novice.: the SSA (Solid State Relay) needs to be carefully chosen as to AC vs DC on the "contacts" because many use zero crossing to switch AC. They differ therefore from mechanical relays .

 

[anorlunda]

A step down transformer might be more expensive than using PWM modulation with transistors.

https://en.wikipedia.org/wiki/Pulse-width_modulation