With a 220K ohm resistor between pin 4 and Vout, I measur about 120mV on the output.hi,
Assuming that the designer has used a 40k from pin #4 to 0V. I would attach a 220k from Vout to pin #4, then check Vout.
E
With a 220K ohm resistor between pin 4 and Vout, I measur about 120mV on the output.hi,
Assuming that the designer has used a 40k from pin #4 to 0V. I would attach a 220k from Vout to pin #4, then check Vout.
E
There is no 40K, just an 8.2K which you found. So does that mean I should use 10.25K in the calculations? (1.25*8.2K = 10.25K)1.25 is 1/0.8
In the example given R2 is 40.2k
1.25 x R2 = 1.25 x 40.2k = 50.25k
Can you find a 40.2kΩ resistor on your board? I don't see one. I see 8.2kΩ.
Ok, so, I was doing exactly what you said and I had soldered a 43K resistor between those two pins. As I was clipping the crocodile clips on, I had to move the resistors out of the way otherwise it would short. Me being me, I applied too much force and ripped off both pad. Luckily it was my test board so i was just looking at other place I could connect it to:Remove the pot and place a 43K resistor between the indicated points
.View attachment 207857
Should get you 5.0 volts out.
2 things:Where you show 43k in blue is fine too, as long as the pad and connections to the 82K and the IC pin 4 are intact. . It looks like a fairly simple circuit, and the 43K should give you 5 volts. If not, as you say, there may be something else wrong on the board.
When you power it up, what voltage are you seeing at pin 4?
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