Heating Pad not hitting max temperature

I can’t seem to get this to go above 30C? Whether I have it hooked up directly to 5V on my UNO or off a digital pin on my Nano V3.0 Board it just doesn’t seem to heat up as it does in the chart (~60C in 2 min) or the video.
Anyone else had better luck with it? I am trying to make a dough proofing box, so doesn’t need to be that hot, but if limited to 30C it will take forever and may not keep up with any thermal losses.

Hi Dion,

Depending on your source it might not be able to pull enough current to reach 60 degrees. Can you share a picture of your setup?

Hi Jack,

It’s a Nano V3.0 with a 100K NTC thermistor on A0 and an LED with 220ohm resistor to signal when element is on.
I also have a 10k pot to set target temp between 20-30C.


Hi Dion
If you have got it sitting out on the table like shown you are never going to get the thermostat to 30º. It is only 3W which is not much. If you enclose it in something or wrap it up you will have a better chance.

I think this bit of the text says it all
" ideal for things like hand-warmers and other heated garments."
Cheers Bob
Edit
Just had a bit of a study of your pix. Very hard to tell what is going on. Even the parallax error with the camera does not make it easy to tell which Arduino pins are connected to what. A schematic would be helpful.
It looks like you are trying to drive the heater directly from an IO pin. If so can’t do that. The heater needs 600mA and the IO pin will only supply 20mA so well short.
post a schematic showing EXACTLY what you have and we can go from there.
Cheers Bob

2 Likes

Thanks Bob, I think you’ve nailed it. It’s the low current available.
I’ll have to add an additional power source and a switch of some sort.

Hi Dion
If you want to switch it with the Arduino a Mosfet configured as a low side switch would be the easiest way. You will need a power supply for the heater, I would suggest one that is capable of at least 1A.
Cheers Bob

2 Likes

Operating Current: ~600mA. Maybe it’s not getting sufficient current.

Hi Ila
If it is being driven from a GPIO you can bet on it
Cheers Bob