Old counter chips. Need replacement. Urgent.
Old counter chips. Need replacement. Urgent.
(OP)
Hi,
I'm in a real pinch here. Printing press with old counter chips. I think Teledyne/Chrystalonics, Type 374AL/CL.
Are there any replacements? Or do they still exist. A sudden answer is appreciated.
I'm in a real pinch here. Printing press with old counter chips. I think Teledyne/Chrystalonics, Type 374AL/CL.
Are there any replacements? Or do they still exist. A sudden answer is appreciated.





RE: Old counter chips. Need replacement. Urgent.
Are you sure that it's a counter and not a octal latch?
If it does turn out to be an octal latch, you MIGHT
try replacing it with a 74LS374. Please watch fanout/fanin
as the LS parts have twice the input requirements from
the L series part. You might also look into the BI-CMOS
versions, however, there are pull up requirements that
might make it more cumbersome than just swapping in
'LS parts.
Best of luck!
Cheers,
Rich S.
RE: Old counter chips. Need replacement. Urgent.
Yes it is a counter. There are three of them that ramp the speed set-point up and down. The output from the counters are fed to an old D/A and the analogue setpoint is taken from there. We have found the defective chip and are trying to rearrange the circuit to circumvent that defective chip. We will get a somewhat lower resolution, but that seems to acceptable to the printers.
The 374 is not preceded by any letters or numbers - this seems to be one of those slow speed high level devices that were used before CMOS 4000 series took over that niche.
The question is still open: is there any equivalent or replacement? I have tried Siemens and Telefunken LSL families, but they do not have bidirectional counters. Motorola perhaps, but I haven't contacted them (=found the right person) yet.
RE: Old counter chips. Need replacement. Urgent.
RE: Old counter chips. Need replacement. Urgent.
We brought out the good old PicMaster and a 16C57. But before we had figured out how much interfacing we needed to work with the 12 V signals, we found that the 0.1 percent resolution wasn't needed. So we crippled the counter and are now running eight bits. That seems to be OK with the printers. All is well and the press is spewing out magazines again.
But, of course, we still need a replacement.
Thanks for your efforts!
RE: Old counter chips. Need replacement. Urgent.
RE: Old counter chips. Need replacement. Urgent.
RE: Old counter chips. Need replacement. Urgent.
That seems to be exactly what we need. Thanks a lot
Do you know any Scandinavian distributors? Or European.
RE: Old counter chips. Need replacement. Urgent.
IC brokers for Europe
http://www.doom.com/
http://www.dialelec.com/266.html
RE: Old counter chips. Need replacement. Urgent.
If you know what it is supposed to do, it may be simpler
to redesign it with modern IC-s.
<nbucska@pcperipherals DOT com> subj: eng-tips
RE: Old counter chips. Need replacement. Urgent.
Thanx
RE: Old counter chips. Need replacement. Urgent.
RE: Old counter chips. Need replacement. Urgent.
Thanx
RE: Old counter chips. Need replacement. Urgent.
It could be the D/A chip. It is an old Analog Devices chip, the one with a golden lid. It is a current source D/A and feeds a 560 ohms resistor, so the output signal is quite low. It is then amplified in an opamp with rather high gain.
If the speed is varying in the morning (before the heat has built up in the cabinet, I would suspect either the opamp itself (it is usually socketed and easy to change) or the potentiometer in the feedback. Small variations in the potentiometer division ratio can make the output change quite a lot.
These presses are getting quite old and the electrical cabinets are usually placed close to them. I have had cases where the printing ink and paper dust has aggregated on the PCB and made operation unstable. Have you tried to clean both sides with alcohol? It does help in many cases.
Or shall we join forces and program a micro to do the job? Make a little mezzanine board that plugs into the three sockets and contains micro and 12 V interfacing?
RE: Old counter chips. Need replacement. Urgent.
with a new design. Do you know the input signals/sensors and the required outputs? Do you have schematics or can you
get one ?
If it is so old, it must be two layer PCB -- it should be easy to trace out the schematics. It may be harder to find the data of the old IC-s.
<nbucska@pcperipherals DOT com> subj: eng-tips
RE: Old counter chips. Need replacement. Urgent.
Also i am missing quite a few drawings from the Harris since it was bought second hand quite a few years ago that i was still a student in UK.
Whatever drawings i have i ve also made them in electronic form so if you intrested i can send you a copy of the cd.
RE: Old counter chips. Need replacement. Urgent.
I think so too. I have actually recommended the customer to install modern equipment on that machine. But before this happens, it needs to be kept running for a year or so. The 10 bit to 8 bit conversion seems to work quite well. I think we should leave it so.
Interesting that you have the drawings in electronic format. As you know, we are not supposed to reveal mail addresses here. But a fax number is OK, I think. So, here it is: +46 586 12316. Fax me your mail address and I mail you mine.
RE: Old counter chips. Need replacement. Urgent.
There nothing in the rules about mail,E-mail, phone etc.
but if you post your URL, use non-machine readable format
-- see mine.
<nbucska@pcperipherals DOT com> subj: eng-tips
RE: Old counter chips. Need replacement. Urgent.
I have send you a fax with my details. feel free to mail me any time.