(Off Topic) NON Stompbox related, but Electrics related, HELP!

[nordine]

Hey there, i've been scratching my head all day, and had to come here and ask for help becuase im getting more than frustrated
this is it:

I have an intercom/electric door opener in my house, and it started failing sometime ago. It wouldnt open the door, it would sometimes, but sometimes not.

this is the map:


SO, we have the power source (12V), the switch and the electric lock. The installation was old, so i removed all cables and put some fresh cables everywhere

WHATS CRAZY is that when i hit the switch, it opens the door, i hit it again, it opens the door. then i left some time, try again and it wont open the door
-The red dots and black dots are leads. Thinking the switch was busted, i bypassed it connecting the red leads, nothing happens
-If i connect the black leads, it always opens the door. After that i can open the door using the switch, if some time passes by, it wont open again, but if i connect the red dots, it will, IM PUZZLED 
-The cable is checked and fine, fresh and robust cable

Any help?? or ideas?

[Sanguinicus]

Try changing the battery and/or the lock. Seems obvious given you've changed the wiring and tested the switch.

[Earthscum]

Here's the logic I'm thinking... if you can touch the black leads, and then the button works again, unless you let it sit for awhile, it seems to me there's some kind of charge building up? Maybe try something like a 1-10M bleeder resistor across the black leads and see what that does for you. I'm kinda thinking along the lines of how ya stomp a box that just has a cap input with no bleed resistor to ground, you get a pop. If you have a bleed resistor, it allows the cap to stabilize instead of building up a charge that gets released when the circuit is closed.

And, on that not, maybe check the lock for connections, if you can disassemble it. Make sure that sucker is still water-tight. Moisture will do funny things... like when you get moisture in your car's distributor cap, it starts firing across to the wrong plugs. I have seen quite a few welders arc and whatnot (and shock the living crap outa me) because of dust. Dust will hold charges like a cap, as well as cause resistive shorts (keep your car's battery clean and it lasts alot longer).

Hopefully that helps ya, if not at least give ya some other ideas maybe. Good luck!

[nordine]

Try changing the battery and/or the lock. Seems obvious given you've changed the wiring and tested the switch.

12VAC come from a transformer, no battery here. i also thought (ive thought about avery aspect of this) the transformer might be faulty, but it does the job

about the lock.... how do they work? do they have any capacitor inside? that would explain things

[nordine]

Here's the logic I'm thinking... if you can touch the black leads, and then the button works again, unless you let it sit for awhile, it seems to me there's some kind of charge building up? Maybe try something like a 1-10M bleeder resistor across the black leads and see what that does for you. I'm kinda thinking along the lines of how ya stomp a box that just has a cap input with no bleed resistor to ground, you get a pop. If you have a bleed resistor, it allows the cap to stabilize instead of building up a charge that gets released when the circuit is closed.

And, on that not, maybe check the lock for connections, if you can disassemble it. Make sure that sucker is still water-tight. Moisture will do funny things... like when you get moisture in your car's distributor cap, it starts firing across to the wrong plugs. I have seen quite a few welders arc and whatnot (and shock the living crap outa me) because of dust. Dust will hold charges like a cap, as well as cause resistive shorts (keep your car's battery clean and it lasts alot longer).

Hopefully that helps ya, if not at least give ya some other ideas maybe. Good luck!

good ideas man, its of great help! ....the bleeder resistor and the dust holding charges.... will implement these tomorrow, thanks a lot!

[nordine]

If i'd put the switch where the black dots are, this would solve the problem, but WHY???

The only distinction i can make about putting together the red leads versus the black leads, is that i get "more sparkles" (lol) when i connect the black leads than the red ones. a "greater discharge", like it has more voltage at the black leads (i might be talking BS at this stage, but bear with me).

The cable from the red dots to the black dots is only 8 feet long. These types of electric locks can work with 300 feet cables, so i cant even explain this

[jefe]

about the lock.... how do they work? do they have any capacitor inside? that would explain things

The lock probably uses a solenoid, try searching for that.

[Earthscum]

about the lock.... how do they work? do they have any capacitor inside? that would explain things

The lock probably uses a solenoid, try searching for that.

Aye. This is what I was trying to explain about the dust and dirt. I've had solenoids fail on me in the past from dirt. The dirt and dust is what would be holding a charge and acting like a cap in the lock mechanism. I doubt there's a cap in there.

As far as the 8ft cable goes... what gauge is it? I wonder if that could be an issue. I still would try a bleeder resistor across the leads and see if that does it for you. If so, it will help ya track down and fix the problem right (resistor would just be a troubleshooting crutch, I wouldn't rely on it to fix the problem).

I just remembered having kind of the same issue with my tube power supply. When I put in shielded cable, I quit having so many issues, but ended up using that to track down the problem (ended up being the ground to chassis... my grounding scheme was shoddy).

[kdowqo]

im not completely  sure i understand u correctly but by the look of your "schematic" the upper black dot and the upper red dot should be equal and the lower black and red dot should be equal but since they're not u probably have a bad connection somewhere between them, have you checked for continuity between the upper dots as well as between the lower dots

[nordine]

@Earthscum will try doing two things: cleaning the electric lock and reducing the gauge of the cable (btw, before failing, the cable was as as thick as the one i put yesterday)

@kdowqo yeah ive checked continuity, thing is, its not that the cable does not connect the leads, its that it needs like a "push" to start working (cables cant be pushed, but "something" needs to be "pushed", the transformer? the lock?)