This method will also allow us to alter Ek for different print media. So in the UI, you would select what you are printing on, and it would adjust the striking force automatically.

To test all that, you would need something that can generate electrical pulses of different lengths, voltages, and profiles. A straight square wave might not give the best results. PWM will probably be the way to go.

Generally this (PWM) isn't a great idea with solenoids for something like this, unless you love heating them up and need the solenoid to HOLD after striking. Just pulse it for slightly longer for thicker media. For example, with a 23-800 or a 26-1200 solenoid you might pulse it for 10ms @ 24v on paper. Increase in 5ms increments and see where that gets you on the next thickness media. Increase in small amounts until you get it just right. You'd really only ever want to duty cycle a solenoid to HOLD it in a certain position, which is pointless in something like braille pressing; a quick strike and quick release should be your goal. Remember to lock out the solenoid from being fired too frequently in the code. For example, I might recommend having it fire no more than 10 times per second to start with. Print a bunch of stuff, and check the temperature. Decrease the enforced OFF time accordingly depending how warm it's getting. You can really get them machinegunning pretty quickly with proper drivers and software. A skookum return spring will help increase speed as well.

Glad you guys got the solenoid thing working, I guess I wasn't crazy with the solenoid suggestion after all :)