john.luckins
pfm Member
I just built a -5V reg using the old manual for guidance so:
AD817
TL431
R5 =249R
R8 =1k
R9 =1K
D2 = 1N5333B
But on test I only get 2.64V out.
This is the first ALWSR I have built that hasn't produced the expected output voltage. Any ideas please?
Cheers
Ian
Tricky. Have you got the Zener the right way round? The circuit diagram recommends an LED for D2 so I would give that a try. Make sure it has a resistive load to sink at least 5ma. I'd recommend 100 ohms or lower especially if you are using the tracking pre reg. Is the LED D1 alight?