Thread: Kit 74 troubleshooting

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I recently bought a Kit 74 to use to control christmas lights. I have had trouble, but i finally got it working with the computer. Now my only problem is i am getting voltages when i should not be. When the relays are in the off positions, some of the outlets are getting anywhere from 30 volts to 110. I dont know enough about electronics to troubleshoot this, so i was wondering if anyone could hep. The instructions that came with the board said if i wanted to pull more voltage to solder heavier wires onto it, so i soldered 14 gauge wire on the bottom because thats what i had and i knew it would work. if anyone could help me that would be great!

There are NC (normally closed) terminals and NO (normally open) terminals meaning, depending on how you connect you either have voltage all the time until a signal is given, OR you have no voltage until a signal is present.

Are you sure you are hooking up to the right ones, just a thought?

Don

I do have it wired like that. When i turn the circuits on with the computer, they have 120 volts, but when i turn them off, not all of them are at 0

Originally Posted by chuckers389

I do have it wired like that. When i turn the circuits on with the computer, they have 120 volts, but when i turn them off, not all of them are at 0

Have you tried unplugging the board from the computer and then test to see if any voltage is still passing ? If there is that will tell you if there is something internally wrong with any of your relays. If power drops, then your problem is coming from your controller.

with the controller unhooked from the computer, i was getting the same readings as when hooked to the computer

Originally Posted by chuckers389

with the controller unhooked from the computer, i was getting the same readings as when hooked to the computer

if your relays are still passing power when the board is unplugged, then it sounds like a bad relay, or a wiring issue.

is there some way i could have screwed up the relays when building it, because it is brand new. But i assembled it myself

Originally Posted by chuckers389

is there some way i could have screwed up the relays when building it, because it is brand new. But i assembled it myself

I would examine the contact side of the relay. Make sure none of your solder joints are touching. (I am assuming you soldered the relays in ? ) You might have a connection between your COM and NO pins on the affected relays.

I was going to take off the wire i soldered onto the bottom and see what results i get when i do that so that i can isolate the problem.

Can you post some close up pictures of your solder job?

Those contacts are pretty close together and it sounds to me like you may have a tiny bit of solder bridging the gap between the contacts.

This might be a very high resistance connection causing you to get less than 120 volts across, but still getting something.

If this is the case, it is also probably getting hot.

Whenever I want to run something that requires a lot of current from a kit 74, I use the on-board relay to drive a secondary relay with huge contacts that can handle 20 or 30 amps.

The Kit 74 turns on the big relay coil. The big relay contacts turn on your device.