OK so I have been looking all over, I have heard about simple testers using op-amps, windo comparators etc. but can't seem to work this out...
In my industry (entertainment lighting) there is a specialised need for a tester that checks 6 circuit "multi-cable". These cables could have almost any compbination of series or paralell incandescent lamps connected to them - all 120v types, many possible wattage combinations. However, as well all know the resulting resistance will be very low, but NOT dead short.
There are commercial testers out there that use bi-color LEDs to show the state of any given hot/neutral pair of connections on the 6-circuit connector:
- Green for a good lamp (low resistance)
- Red for a short (no resistance, sometimes also sounds a piezo sounder)
- Off for open circuit
I don't know if the LEDs are two wire or three wire.
I do know that the ciruit has a very low quiescent state current - so if it is not testing anything it is essentially "off" drawing little or no current.
I know that the circuits are small, I mean low component count, because they fit inside an amphenol 19 pin connector (called socapex) and these things are a tight fit once you shove a battery in there as well!
Anyone? Help would be greatly appreciated....
Andy
In my industry (entertainment lighting) there is a specialised need for a tester that checks 6 circuit "multi-cable". These cables could have almost any compbination of series or paralell incandescent lamps connected to them - all 120v types, many possible wattage combinations. However, as well all know the resulting resistance will be very low, but NOT dead short.
There are commercial testers out there that use bi-color LEDs to show the state of any given hot/neutral pair of connections on the 6-circuit connector:
- Green for a good lamp (low resistance)
- Red for a short (no resistance, sometimes also sounds a piezo sounder)
- Off for open circuit
I don't know if the LEDs are two wire or three wire.
I do know that the ciruit has a very low quiescent state current - so if it is not testing anything it is essentially "off" drawing little or no current.
I know that the circuits are small, I mean low component count, because they fit inside an amphenol 19 pin connector (called socapex) and these things are a tight fit once you shove a battery in there as well!
Anyone? Help would be greatly appreciated....
Andy