Analogue systems

OK, I can answer this for you, but please *listen* closely for your own
module's safety.  Depending on the shunt fold back protection of your PSU,
getting them reversed may require you to change all of the semiconductors in
the effected devices.  I say this only because I enjoy (for lack of the real
word) dyslexia and am constantly getting things like this reversed.

The Analogue Systems modules get their power via a 16 pin dip socket (IC
socket).  What they've done is rather clever, double-doubling up the four
voltages in groups of four wires each of a standard ribbon cable, thus
allowing for very easy power distribution without compromising the current
limit of the comparatively small gage wires of the ribbon itself.

The power distribution and four pin groups on this socket are as follows:

Group 1 (Ground): pins 1,2,16,15

Group 2 (+12):  pins 3, 4,14,13

Group 3 (+5 - see footnote): pins 5,6, 12,11

Group 4 (-12): pins 7,8, 10, 9

These pin outs are identical on all A Sys boards.  Note that +5 will not be
required on every module you purchase and you should consult A. Sys
regarding which may be effected.  All modules that have a LCD display will
require it and there are more as well without displays.

If you don't wish to deal with the ribbon cable, I use what's called a 'surf
board" connected to only one side of the DIP socket (either pins 1 - 8 or 9
- 16), as it will allow for thicker gage wires and eliminate the need to
double them up.  It also makes it a hell of a lot easier to terminate the
other end to a four pin Molex, which I think you're describing here.

One thing I suggest - once you've connected it, BEFORE YOU LIGHT IT UP, test
these connects at THEIR SOURCES.  Buzz out the four voltages FROM THE POWER
SUPPLY TERMINALS to LOCATIONS ON THE MODULE'S PCBA WHERE YOU ARE CERTAIN
THESE VOLTAGES ARE ROUTED.  For instance,  an ohm meter,  beeper or wire
continuity tester from the positive 12 volt terminal on the PSU to pin 4 of
any TL074 or 084 IC.  From the negative 12  terminal of the PSU to pin 11 of
the same IC.  If you're getting continuity at those two places, you can be
certain ground is going where it should.  If it isn't at least the module
won't blow, it will just not allow for a return (current flow) and the thing
simply won't turn on when power is applied.

On TL072's and 82's, which are quite common on A. Sys modules,. +12 is found
at pin 8 and -12 at pin 4.  Doing this allows you to test your Molex
termination -and- your DIP socket end at once.

Make sure to wear a ground strap when sniffing around PCBAs.  There could be
CMOS afloat, just waiting for tha fateful discharge.

Hope this helps.

- Peter




terrymcfrench wrote:

> Hi,
> 
> Does anyone have the pin setup for AS modules?  I have an american
> PSU (4 pin) but I'd like to get some AS modules.  Doepfer has their
> pin setup on their website so you can figure out what you'd need for
> the conversion, but so far I haven't been able to find that info on
> the Analog Systems site.
> I'd appreciate any help.
> Thanks
> 
> 
> 
> 
> To unsubscribe from this group, send an email to:
> analogue_systems-unsubscribe@yahoogroups.com
> 
> 
> 
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
> 
>