Something Wrong Here?

[dantwomey]

I took my first shot at a simple bipolar regulated supply and it looks like something has gone awry? When I first fired it up I go a perfect +/-15.7VDC on each side. This is higher than the desired +/-12vdc that I was looking for so I changed R1/R2 to 800 ohms. No luck, same output voltage.

Thoughts anyone?

Regards,
Dan

 

[rayma]

What is the input DC voltage (pin #3) to the positive regulator?

 

[dantwomey]

Best guess is voltage in is the same voltage out 15.7vdc. Which make sense because AC input is around 12-13V.

Regards,
Dan

 

[Ben Mah]

Are you testing with load? Do you have the LEDs in the circuit and are they on?

 

[jackinnj]

Diode polarities reversed?

 

[rayma]

Best guess is voltage in is the same voltage out 15.7vdc.

Measure it and see. The dropout voltage is around 1.5V-2.5V across the regulator.

 

[rayma]

Diode polarities reversed?

That would certainly do it.

 

[dantwomey]

Diode polarities reversed?

Removing the diodes would be the easiest test. More later today when I have time.

Regards,
Dan

 

[dantwomey]

Diodes in backwards. A simple mistake. All is well now.

Thanks for everyone's help!

Regards,
Dan