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Question about DC power supply

Here's what I've done now:

Per the advice of the guy I bought this from -

1. I jumped the two 'outside' wires on the voltage adjustment knob on the inside of the case.
2. When I did this, I was able to adjust the voltage all the way up to 14.97 VDC.
3. However, when I reached a little over the halfway point on turning the knob, the voltage started to drop back down.

The guy I bought it from thinks the adjustment knob 'pot' is bad. There are three wires going to the knob, and all three are connected to the inside of the knob. I'll check the connection on the board later. It's putting out the correct voltage, I'm just unable to adjust it up where it needs to be without jumping the knob wires.
 
Agreed. At least it sounds like the voltage regulator is fine. Perhaps the voltage adjust pot is indeed bad. One side of that pot should go to ground thru another resistor, one side to the output thru another resistor and the centre pin of the pot should go to pin 4 of the LM723 regulator chip.

My ps has a house chip so I can't say for sure which one it uses.
 
So back to my original issue -

As I mentioned, when I jump the two outside wires on the pot, I am able to get and adjust a voltage reading. Can anyone give me some advice on what might cause this? Obviously some kind of discrepancy exists either in the wiring to the pot, or in the pot itself. It seems like it would be an easy fix, I just don't know where to start. Obviously, I cannot use this by having the two wires jumped all the time. Thanks much.
 
Goes the easiest and cheapest route and that would be replacing the potentiometer because the regulator is obviously good and the control lead from the potentiometer is good.
 
Goes the easiest and cheapest route and that would be replacing the potentiometer because the regulator is obviously good and the control lead from the potentiometer is good.

Thanks for the quick reply - what is the correct way to wire one? There's only three wires to it. The middle one I tested (black) is ground - good continuity check on that. Is it just a matter of testing the two outside wires until I get the desired effect?

I've never dived into electronics too seriously before. I did wire up a relay for some spot lights on my motorcycle, but other than that not any experience with anything like this. Is there a capacitor on there I need to watch out for? Any idea what rating the pot is? Thanks.
 
Thanks for the quick reply - what is the correct way to wire one? There's only three wires to it. The middle one I tested (black) is ground - good continuity check on that. Is it just a matter of testing the two outside wires until I get the desired effect?

I've never dived into electronics too seriously before. I did wire up a relay for some spot lights on my motorcycle, but other than that not any experience with anything like this. Is there a capacitor on there I need to watch out for? Any idea what rating the pot is? Thanks.

No idea about the value, but it should be marked on the pot's housing. Just record which wire is connected to which terminal and wire the new one exactly like the old one.

You could call or email Astron and ask them. They might even provide a copy of a manual with a schematic and parts list!
 
Here's the latest:

I de-soldered the two outside wires and hooked them both up to the pot terminal closest to the outside and now she adjusts all the way up and down like she should. The pot connector on the inside of the case is not connected to anything. Just the ground wire and the terminal on the outside. Is this hurting anything? I hooked up a motorcycle headlight to check it out and she dims/brightens when I rotate the knob and it draws up to 10 amps for the headlight. Do I understand correctly that the more amperage needed the more amperage will be shown on the meter? And, for example, if I power something that requires 20 amps I should be able to decrease the amperage if I need to in order to troubleshoot something?
 

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