Hi do-it-yourselfers, I have developed a design for a constant current regulator whose output is a constant 1.11 ma at up to about 160 volts D. C. The circuit is very simple, and uses an LM334Z constant current regulator, a high voltage transistor and a couple of resistors. The power supply for it is a small dual primary transformer used as an isolation transformer for safety, and a simple half-wave rectifier. All the parts cost less than $15. The output current can be set to other values by varying one of the resistors.
Why use such a high voltage? Because it allows immediate predictable production rates from the moment power is applied. On the other hand, using 27 volts requires quite a long time for the current to ramp up to the desired value unless one adds salt, baking soda or some CS from a previous batch. If any of you want the schematic, send me an E-mail off-list, I will send you my address so you can send me a SASE, and I will mail it to you. Sorry, I don't have a scanner yet to send it electronically. PLEASE don't request this unless you are experienced with electronics. Unlike wiring a few 9 volt batteries in series or using a wall wart, this design has voltages which can prove to be quite shocking. I will not be responsible for any adverse results of using this design. --Steve
