Hello there, I'm designing circuit for checking power strip that has 3 Polarity which is Line Neutral Ground

I'm try to check these 3 elements together
1.Any Line cannot be short circuit (3 possible pair short L-N, L-G, G-N)
2.Every each line must have continuity from plug head to socket (e.g. if you connect battery from L plug to L socket it must have close circuit)
3.These 3 polarity cannot swap inside power strip (e.g. if you connect battery from L plug to N socket and it have close circuit then it's a defective ) (5 possible wrong swap A.Only L correct B.Only N Correct C.Only G correct D.Every line swap to 1 line ahead E.Every line swap to 1 line backward)

I've design using this website https://www.falstad.com/circuit/circuitjs.html
You can copy this code and go to File > Import from text

$ 1 0.000005 9.78399845368213 41 5 43
w 528 384 528 432 0
162 528 320 528 384 2 default-led 1 0 0 0.01
w 528 432 480 432 0
w 528 272 528 320 0
w 480 272 528 272 0
d 320 304 320 272 2 default
w 128 304 192 304 0
w 480 272 480 320 0
w 320 272 480 272 0
w 480 384 480 432 0
w 480 208 480 272 0
w -16 192 -16 368 0
s 208 608 256 608 0 1 false
w -16 608 208 608 0
w -16 608 -16 432 0
v -16 432 -16 368 0 0 40 5 0 0 0.5
w 128 192 -16 192 0
162 480 384 480 320 2 default-led 1 0 0 0.01
w 384 208 480 208 0
w 288 192 320 192 0
w 288 208 288 192 0
w 192 208 288 208 0
s 272 352 320 352 0 1 false
w 320 304 320 352 0
w 272 304 272 352 0
w 128 304 128 352 0
w 80 304 80 352 0
w 272 288 272 304 0
w 80 288 80 304 0
w 80 224 80 256 0
w 272 224 272 256 0
v 272 256 272 288 0 0 40 5 0 0 0.5
v 80 288 80 256 0 0 40 5 0 0 0.5
w 320 240 320 272 0
w 128 240 128 304 0
w 128 224 80 224 0
178 320 192 384 192 0 1 0.2 6.921310737641629e-35 0.05 1000000 0.02 20
178 128 192 192 192 0 1 0.2 -2.2204460492503108e-20 0.05 1000000 0.02 20
s 176 496 224 496 0 1 false
s 384 496 432 496 0 1 false
s 240 560 288 560 0 1 false
w 80 496 176 496 0
w 224 496 272 496 0
w 272 496 384 496 0
w 432 496 480 496 0
w 80 560 240 560 0
w 288 560 480 560 0
w 480 496 480 560 0
x 53 494 66 497 4 24 L
x 265 526 282 529 4 24 N
x 487 508 505 511 4 24 G
d 80 560 80 496 2 default
w 192 304 192 432 0
w 80 352 80 496 0
162 384 432 432 432 2 default-led 1 0 0 0.01
w 432 432 480 432 0
w 384 432 192 432 0
w 480 432 480 496 0
s 80 352 128 352 0 1 false
w 272 352 272 496 0
w 480 560 480 608 0
w 272 224 320 224 0
w 256 608 480 608 0
w 496 -16 592 -16 0
w 496 -80 496 -16 0
w 240 -16 448 -16 0
s 384 80 448 80 0 0 false
s 384 48 448 48 0 0 false
s 384 16 448 16 0 0 false
w 448 16 592 16 0
w 656 -16 656 80 0
w 448 80 656 80 0
w 176 80 384 80 0
w 208 -16 208 48 0
w 208 48 224 48 0
w 624 48 448 48 0
w 624 -48 624 48 0
w 592 -16 592 16 0
w 240 16 384 16 0
w 240 -16 240 16 0
w 176 -16 176 80 0
s -112 -32 -48 -32 0 1 false
s -176 -32 -112 -32 0 1 false
w 304 -48 624 -48 0
w 208 -48 208 -16 0
w 256 -48 208 -48 0
w -112 32 -112 -32 0
x -178 -95 -165 -92 4 24 L
x -114 -93 -97 -90 4 24 N
x -57 -92 -39 -89 4 24 G
v -48 -32 -48 32 0 0 40 5 0 0 0.5
162 -48 32 -112 32 2 default-led 1 0 0 0.01
162 -112 32 -176 32 2 default-led 1 0 0 0.01
w -176 -16 -176 -32 0
v -176 32 -176 -16 0 0 40 5 0 0 0.5
w 176 -80 176 -16 0
w 656 -64 656 -16 0
w 656 -176 656 -128 0
w 176 -192 176 -128 0
v 176 -80 176 -128 0 0 40 5 0 0 0.5
x 162 110 227 113 4 24 PIN\sG
x 568 106 666 109 4 24 Socket\sG
w 304 -192 176 -192 0
162 656 -128 656 -64 2 default-led 1 0 0 0.01
w 560 -176 656 -176 0
w 464 -192 496 -192 0
w 464 -176 464 -192 0
w 368 -176 464 -176 0
x 549 72 646 75 4 24 Socket\sN
x 189 74 253 77 4 24 PIN\sN
x 215 39 275 42 4 24 PIN\sL
x 521 42 614 45 4 24 Socket\sL
w 448 -80 448 -16 0
w 256 -80 256 -48 0
w 448 -96 448 -80 0
w 256 -96 256 -80 0
w 256 -160 256 -128 0
w 448 -160 448 -128 0
v 448 -128 448 -96 0 0 40 5 0 0 0.5
v 256 -96 256 -128 0 0 40 5 0 0 0.5
w 496 -144 496 -80 0
w 496 -160 448 -160 0
w 304 -144 304 -48 0
w 304 -160 256 -160 0
178 496 -192 560 -192 0 1 0.2 -0.23788774602167606 0.05 1000000 0.02 20
178 304 -192 368 -192 0 1 0.2 0.23788774602167612 0.05 1000000 0.02 20
w 224 48 384 48 0
x -55 630 10 633 4 24 PIN\sG
x 326 367 390 370 4 24 PIN\sN
x 112 373 172 376 4 24 PIN\sL
x 16 351 77 354 4 24 Soc\sL
x 204 371 269 374 4 24 Soc\sN
x 499 619 597 622 4 24 Socket\sG
x 532 337 694 340 4 24 Good\sindi.\sLED
w 48 0 912 0 0
x 793 -18 861 -15 4 24 Circuit
x 761 29 894 32 4 24 Test\sProduct
w -176 -32 -176 -80 0
w -112 -32 -112 -80 0
w -48 -32 -48 -80 0

The first circuit will check only the short circuit

When we test just put plug head from product to socket of tester, any of short circuit LED will show (In real environment I will use buzzer instead to test faster)

The second circuit will check defective opening circuit and polarity swap

This circuit have to put product plug to tester socket and put tester plug to product socket.The only way that LED will show is when the circuit is correctly connect and no open circuit.

Here is the final circuit which is quite complicate because it is first and second circuit merging together (they cant directly merge so.. I need to change some components)

And if we remove test product component it will look like this

To use this circuit user have to do 2 steps
1. put product plug to tester socket if no bad LED show (meaning that short circuit) then go to next step
2. put tester plug to product socket if only Good LED show then it pass all 3 tests.

I should design to ease user so they can test more power strip per hour
But the problem is circuit is quite complex if there is some component broken e.g. short diode it will give some false positive which is bad
Any Idea to simplify this? Or other suggestion? I will be very thankful

 

AA

 

hi w,
Are you still searching for an answer to your old Thread problem.?
E

 

A small micrcontroller: drive the three leads at one end and monitor the other ends.

 

AA

I don't think Alcoholics Anonymous or the Automobile Association has the answer .

 

Alcoholics Anonymous do have 12 steps to recovery though.
And only smarties have the answer (or is that a UK only reference?).