[GreenKeys] Loop Supply Circuit and Parts List - AND MORE

[Jack]

ZCZC

 

I have put together a simple 130VDC/60 ma. Loop Supply diagram

and materials list using FOUR readily-available parts.

 

The parts can all be acquired from Mouser Electronics and

should not cost more than $25. The parts can be purchased on-line

and Mouser usually delivers within a few days. I did not include
switches, fuse

holders, indicator lamps, a meter, jacks and an enclosure in the parts
list.

Those things are a personal choice and are left up to the

builder. The parts listed are rated for continuous use.

 

Construction is simple enough that a circuit board would be

overkill. The few parts can be assembled on a perf board or

terminal strip. The adjustable power resistor uses a slider to set

the current. A knob-type variable potentiometer rated for 25W or
better

would have cost a small fortune. However, many of you might

have those kinds of pots in the your TTY junk box. Since this

is a set-and-forget adjustment, the cost of the variable pot

makes no sense. If you are not worried about a few milliamperes

here or there, a fixed resistor could be used at reduced cost.

 

I can send the drawing to anyone who is interested.

 

I have also fine-tuned the "TTY Motor Control" and 

"RS232-to-Loop-Converter" circuits and am now working on

PC boards for them. More about these later....

 

73,

Jack K0TTY

 

NNNN

 

 

 

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