Hi all, I work mainly on heavy equipment (dozers, scrapers, cranes, etc.) and over the past decades the technology has changed like everything else. Most have some type of actuators and valves and anything else they can figure out how to put in the mix. Some are just basic dc controls where others are pwm and other schemes. My largest problem is being able to test some of the devices without just going the parts changer route. Awhile back I put together a simple box with a variable dc-dc pwm buck boost power supply and a high current supply for heavier devices. The problem is that the pwm supply runs at 15 khz which is way above the spec (-1 khz) for many devices. I have been thinking about modifying the power supply and limiting it to 300 hz which i believe would satisfy most specs. But on second thought (dangerous I know) maybe finding a variable frequency and variable pwm supply would be better. The max current for the supply is 4 amp which I have never reached and all of the machines are 12 or 24 volt. I have not been able to locate anything that will allow me to vary the pulse width and frequency, only one or the other. My device will operate from 12-24 vdc, simply because most work is done somewhere without ac power and I don't want to go the inverter and extension cord route. With the amount of wiring and connectors associated with many of these controls taking them apart just to check can open another can of worms. Thanks for ANY suggestions or where to maybe locate such.