I have already built the +5vdc version of the JSR-01 reg...but I am having trouble building a -5vdc version.
I have completed it but now get -7.6vdc on the output....I have done the following
input is -22vdc
H1 lamp is on
R10 = 47 ohms
C10 = 100 nF
C11 = Tin jumper
all above are done and ok
r4 wire bridge changed to r5 for neg version
6v8 zener in z2 position
t1 t2 and t3 are correct neg regs
tl431aid is in position ic8
pictures to follow
photos as promised
DZ2 should be a LED. Use the same passive parts as for the +5v. When you have changed the DZ2, can you measure all voltages around the opamp? 2.5 V is a good start for pin 2 and 3 on the opamp. The voltages at the pins should be identical within a few millivolts.
Not sure I understand...in the +5v version I used the 6v8 zener in pos z2 and it works fine, but will change it here to a led and take measurements around op-amp :-D
It seems that I may have forgot some details. This design didn't use a LED in this position. The zener should work in forward, meaning plus at the anode. Can you measure the voltages around the opamp?