Any Ideas?
I have a small device that puts out AC 100volts and up to 125ma. It is a constant voltage device with a control to turn up the current. This is already a small amount of current but I need to limit the current to 2ma but keeping the voltage the same. The load varies from a minimum of 500 ohms to 300,000 ohms, there is no way of knowing what the load will be until it is attached. The device works fine with this type of load but the task I have been given is to limit the current to a max of 2ma. So if my load is 500 ohms I would not have to turn up the current control very much at all to get to 2ma but if my load is 300,000 ohms I would have to turn up my control a lot higher to get to 2ma. But in the end no matter what the load is or how high it is tuned up I want it to put out from 0 to 2ma @ 100 volts AC without going over 2ma.The current limiting device needs to be automatic and not adjustable by the user.
The current limiter needs to be simple that requires no power supply and does not put any added load or stress on my device. Seems that I could use a small transformer or a current limiting diode but again I do not want to reduce or change the AC voltage. I am just not quite sure how I can accomplish this.
Thank you
Kim