I bought a powered breadboard which is supposed to give me a regulated +5vdc 1Amp output, OR +15vdc variable / -15vdc variable output. The +5 regulated seems to work fine, but the +15/-15 is totally out of wack..
Here are my measurements with a multimeter, no load conditions:
+5 to ground = +4.96 vdc
+15 to ground = (pot turned full left) -0.16 to (pot turned full right) +14.97 vdc
-15 to ground = (pot turned full left) -14.93 to (pot turned full right)-14.93
As I turn the pot from full left toward the center, the voltage decreases until I get to the center, when it will hit -5.87 vdc, then as I continue to turn toward the right past center the voltage increases again until I am back at -14.93 vdc.
-15 to +15 = (both knobs left) 14.7 vdc. Rotatinig +15 knob to the right increases voltage until max out at 29.8 vdc. Leaving the +15 knob at max, I move to the -15 knob and begin rotating it to the right, voltage decreases until I get to the center position, at which point it is at 21.1 vdc, then continuing to the right the voltage increases until max out at 29.8 vdc.
I don't think it is supposed to function this way, though I am known to be wrong about these things I expect the -15 to ground to give me 0 vdc when turned left, then decrease until max at ~ -15vdc. Does anyone have an idea what may be the problem here? Voltage regulator? Possibly something else? Thanks in advance..
Here are my measurements with a multimeter, no load conditions:
+5 to ground = +4.96 vdc
+15 to ground = (pot turned full left) -0.16 to (pot turned full right) +14.97 vdc
-15 to ground = (pot turned full left) -14.93 to (pot turned full right)-14.93
As I turn the pot from full left toward the center, the voltage decreases until I get to the center, when it will hit -5.87 vdc, then as I continue to turn toward the right past center the voltage increases again until I am back at -14.93 vdc.
-15 to +15 = (both knobs left) 14.7 vdc. Rotatinig +15 knob to the right increases voltage until max out at 29.8 vdc. Leaving the +15 knob at max, I move to the -15 knob and begin rotating it to the right, voltage decreases until I get to the center position, at which point it is at 21.1 vdc, then continuing to the right the voltage increases until max out at 29.8 vdc.
I don't think it is supposed to function this way, though I am known to be wrong about these things I expect the -15 to ground to give me 0 vdc when turned left, then decrease until max at ~ -15vdc. Does anyone have an idea what may be the problem here? Voltage regulator? Possibly something else? Thanks in advance..
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