Quote Originally Posted by AutoWiz View Post
MOSFET is the name of the correct part you need here. Because PWM circuits need to be solid state or they will wear out and fail. And solenoids are mechanical in nature so they will not respond well to the pulses of power. I personally am a big fan of the ones made by MKS as they seem to come with the largest heatsinks. You can also use one to drive a heater cartridge for your extruder if you like. They are cheap. Here is a fleabay ad for one: https://www.ebay.com/itm/3D-Printer-...UAAOSwv-ZZ5lXX
You can actually use a solenoid relay, it uses what's sometimes called Bang-Bang control rather than a PID loop with PWM. It basically involves turning the heater fully on and switching it off as it approaches the target temperature, then switching it on as the temperature drops. It's a lot cruder and the temperature is less stable since the heater is either off or going full tilt, you can't turn it on just a little for fine adjustment. It is usable if you're on a tight budget like OP says they are, but they're also wanting to use profiled linear rails so that's sending some mixed messages.