madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: Ang3lus on March 05, 2012, 07:34:14 PM

Title: weird (positive) voltages on the sunking
Post by: Ang3lus on March 05, 2012, 07:34:14 PM
Hey all,

when measureing (9.22v) at tip, i get some weird voltages, i'll just write the weird ones.

(I have only a 5k6 instead of a 5k1 on R5)
(1uf film capacitors)
(1n4004 instead of 1n4001)
(using ICL7660SCPA charge pump)

IC1:

1 5.83
2 5.86

Ic2:

4 Positive voltage
8 8.81v

Ic3:

pins 4 and 5, positive voltages


I'm writing these from the top of my head, but that was weird to me when testing.

I'll write down later the weird ones for sure.

I suspect C17 as a faulty capacitor, could that be the case ?

For the 1uf capacitors i'm using all film, so they are bipolar, no real difference with the + and - there.

zener diode is in the right direction.

also 1n4004 diodes are in the right direction.

same with the 1n34a diodes.

all ics are in the right direction also.

I will up pics later.
Title: Re: weird (positive) voltages on the sunking
Post by: oldhousescott on March 05, 2012, 09:22:34 PM
What version of the board? Your own etching, or a bean? Single-sided/double-sided?

Pics should help. And please list voltage readings for all pins, not just the weird ones.
Title: Re: weird (positive) voltages on the sunking
Post by: Ang3lus on March 05, 2012, 10:23:36 PM
bean board

ic1:

5.90
5.90
2.65
0
9.12
8.50
5.89
5.92

ic2:

5.71
6.07
5.88
6.39
7.85
7.15
5.93
5.88

ic3:

9.12
9.12
0
6.40
9.12
8.52
8.25
6.40
Title: Re: weird (positive) voltages on the sunking
Post by: madbean on March 05, 2012, 10:38:22 PM
The charge pump appears to be malfunctioning or something is making it not operate correctly.
Title: Re: weird (positive) voltages on the sunking
Post by: Ang3lus on March 06, 2012, 09:30:07 AM
this is funny and odd

i've had 3 BAD charge pumps, all from different sources.

4th ones a charm i guess.

i didn't think it was the cause cause i replaced between them 3 times.

ERRR

annoying :(