12V from PWM outputs

I'm sure I'm not using the correct terms for this question, but I want to step up the 5V PWM output from either an Uno or a Nano to power some 12V astronomy dew heaters. I definitely want PWM to try to reduce the power usage, as I'll be running from a battery most of the time. The amperage will be less than 5A total.

Can I do this using just a darlington and at 12V power supply? Will the darlington be fast enough to keep up with the PWM output? I'll likely want to control more than 1 dew heater, but there should be more than enough PWM outputs. I also plan on using a few temperature sensors to get the ambient temperature and measure the dew heater temp so I can adjust the PWM Duty cycle if the dew strip temperature gets too high.

I'm trying to figure out how to diagram what I want to do properly so hopefully I can follow up with a diagram soon if it's not clear what I'm trying to do. It's been a long time since my last electronics class.

Yes, darlington will be fast enough. But you drop a lot of your control voltage across them, with Vce on the the order of 2V.

Much better would be Logic Level N-channel MOSTFET, such as AOD514 if you work with larger surface mount parts.

Or just use a relay module, I don’t imagine you need to turn them on/off faster than a few seconds at a time.

It all depends on how much current your dew heaters require. If you use a darlington pair, like this one from Adafruit TIP120 which can switch up to 5A.

It will be plenty fast to keep up with Uno PWM which is not very fast (<1kHz) unless you do special things.

CrossRoads:
Yes, darlington will be fast enough. But you drop a lot of your control voltage across them, with Vce on the the order of 2V.

Much better would be Logic Level N-channel MOSTFET, such as AOD514 if you work with larger surface mount parts.

Or just use a relay module, I don't imagine you need to turn them on/off faster than a few seconds at a time.

Thanks for the reply

the MOSTFET is probably a good idea.

I want the heaters to be powered using PWM as opposed to constantly. There's not too much heat required, and I can easily calculate the target temperature at if I've have a temperature and humidity sensor.

blh64:
It all depends on how much current your dew heaters require. If you use a darlington pair, like this one from Adafruit TIP120 which can switch up to 5A.

It will be plenty fast to keep up with Uno PWM which is not very fast (<1kHz) unless you do special things.

Thanks for the reply.

The dew heater are less than 5A. Not more than 2A each, and most are quite a bit less.