Hotend heater at lower voltage?

Hi All, we have friends visiting and staying in their trailer. It’s been cold overnight and the Propane regulator has been freezing up and shutting off the heat for them. Bbbrrr. :slight_smile:

I am wondering about using a hotend heater with low voltage PS and Kapton-tape the heater to the regulator. If the regulator is warm enough, the condensation will run off and toasty toes will prevail. We have poured hot water over it and it all works fine for another 3 or so hours.

I have a 3.7vdc/400mA, a 5.2vdc/800mA wall warts. I hooked them up in turn and they both would seem to do the job, but just concerned about Volts/Amps long term.

When hooked up,
3.7vdc WW runs at 2vdc and .5A.
5.2vdc WW runs at 4.9vdc and 1.1A

Neither of them seem to get overly warm, but then I only had them each running for about an hour. They would be running all night.

Is this OK?
Which one?
Is there a better option? I have a 5vdc 2A USB wall wart but would prefer not to use that.

Thanks

The correct solution is to replace the regulator with one that works properly. We have stayed in out trailer during snow storms that left over 12 inches of snow and no heating problems.

Paul

Paul_KD7HB:
The correct solution is to replace the regulator with one that works properly. We have stayed in out trailer during snow storms that left over 12 inches of snow and no heating problems.

Thanks, but there is no “correct solution” this IS a high dollar name brand regulator and made in the US. Condensation caused by expanding gas is common issue (Latent Heat of Vaporization) and when I said cold, I meant 11-F. Couple that with the Latent Heat drop and it is damned cold.

That temp. will cause this issue no matter how it “works properly.” The Propane tanks are in enclosed but not well insulated outside cupboard and eventually the the temp balances inside and outside.

So, back to the question eh?

This is not straightforward !

I don’t understand what your power supplies are powering ?

You need to calculate how much heat you need .

There are safety issues with this - I expect there is a zoning / intrinsic safety issues as the bottles are enclosed .You need to be suitably ( proffesionally ) qualified in these areas before you start .

hammy:
This is not straightforward !

It is if you read the Subject line. I am powering a ...

But, since I seem to have only energized knee-jerk reactions, we are winging it. We have a watt-meter+extension cord and K-type+meter so they can visually monitor the current and temp.

Where I live NO electricity is allowed near a gas bottle setup.
Leo…

If it's only overnight and only in the coldest weather, wrap a "hot hands" type chemical heater around the regulator each night. A plastic bag over the outside will reduce the oxygen getting to the chemical and make it run longer (at lower power.)

If you want an Arduino to control the heater then you need a power transistor. Usually a MOSFET is easiest. But once you've gone to the effort of mounting a transistor then you may as well mount a few more components and make it a thermostat which doesn't need an Arduino to turn it on and off.

The circuit below will work for any voltage between 5V and 30V. The values chosen keep the temperature just around freezing. As a surface-mount board, this is less than half a square inch. I can share the PCB design on OSHPark, if you like.

It is if you read the Subject line. I am powering a ...

Well yes but how many people on here know what a hotend heater is? It would help to know and help to know what their electrical requirements are.

If the regulator is warm enough, the condensation will run off

I'm no expert on such things but I am at a loss understand how ice on the outside can cause a blockage on the inside. I imagine that in really cold conditions propane might freeze in the regulator, but that's just a badly educated guess.

I have a 3.7vdc/400mA, a 5.2vdc/800mA wall warts. I hooked them up in turn and they both would seem to do the job, but just concerned about Volts/Amps long term.

When hooked up,
3.7vdc WW runs at 2vdc and .5A.
5.2vdc WW runs at 4.9vdc and 1.1A

Both are overloaded. Modern wall warts contain a switching converter which, if properly designed, will limit their output current if overloaded, ideally they should be able to operate like this indefinitely, but really this is a case of just because you can do something doesn't mean you should. If they are badly designed they might not withstand this abuse and, in the worst case, might burn out. Obviously there is a risk here. Ideally buy a 5v one that can supply at least 2A.

That's my opinion on the electrics. As for the gas safety side of things Wawa makes a good point.

What's the voltage & current rating for the heater? Or, if you know voltage & wattage you can calculate Current = Wattage/Voltage.

How about a simple incandescent light bulb? We've used them under the hood near the battery for cold weather.

Or perhaps:

  1. a diesel oil heater?
  2. deicing tape/strips for rooves and or pipes