I need to drive a surface covered by a layer of electroluminescent paint. The problem is that I need a voltage about 100V while Arduino can dispense at most 5V per pin (Am I wrong?). Regardless of the specific application what is the best way to solve this?
You are right the Arduino only has 5 volt outputs and you need a switch mode inverter to drive the electroluminescent paint. Apparently at 400hz AC but can be 50hz AC. at 1mA per square inch. From what I have read, DC won't work.
The outputs of the switch mode inverter can be driven by zero crossing opto-triacs which will give you the isolation that you require, these triacs, depending on the device can drive about 50mA to 500mA.
The inverter might not like these opto-triacs and vice Versa, but it's worth a try. Some invertors do not produce a pure sine wave output which can make life very difficult for the opto-triac and may not switch off due to what is called commutation (choose a device with a very high dv/dt rating). A pure sine wave output inverter is expensive.
If commutation is a problem then add a snubber circuit across the opto-triac (have a look on the web).
I would be interested to see what other people say about this,
Dead_Ard
Normally you would drive EL wire with a power supply intended specifically for that purpose; most of these are powered by low voltage DC, and contain an inverter to convert it to AC and some mechanism to kick the voltage up. Some of these have a control line that can be commandeered to switch it on and off with a low voltage signal, or you could use a MOSFET to switch the power supply to the inverter on and off. EL supplies typically don't like it if you disconnect the load from them while they're on - some are damaged by that, others shut themselves off.