D/A converter on K8061 usb interface card blown?

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1

hello Velleman Support

i was doing measurements and laborations on my K8061 interface card when
analogchannel 1 output was shorted to ground with maximum voltage(10 volt)on.

after that did happen i didn’t get any linear output between 0-10 volt or 0-5 volt on any of the analog outputs. just some blinking on all of the analog channels at same time.
the analog outputs does not answer on any command send to the K8061
but analog inputs are still ok and all digital inputs and outputs are ok too.

i already searched for the A/D converter TLC5628CN but didn’t find any IC’s at the most common electronic firms here in Sweden.

can i use some other A/D as replacement?
Thank’s for reading this and helping me out.

2

Most probably only the output amplifier IC8 (TLV2374) has damaged.
This damaged amplifier may load the power supply too heavily and cause the IC9 is also getting too low supply voltage. Then all the eight digital outputs are not working.
Please remove IC8 and check if the digital outputs 5 to 8 are then working OK.

You may also replace both IC8 and IC9 with IC10 and IC11 and check if all the eight analog outputs work OK.

3

i have tested to replace both IC8 and IC9 with IC10 and IC11 and the analog inputs worked ok put the outputs were acting same as before

the 4 quad op amps on my USB card are named TLV 2741 and not TLV2374

the package is named VM140 and i have 3 more K8061 cards and i could go testing to replace some more IC:s but i am afraid of losing some more IC:s

i also tested to remove the IC7 D/A converter and the constantly activated outputs did go down.

4

The TLV2741 is currently used in the VM140. In the old circuit diagram there was TLV2374.
It seems the D/A converter IC7 has really damaged.
It is indeed very strange how short circuiting the operational amplifier output can damage the D/A converter IC7.

5

ok first i must say i’m sorry for taking up supporttime and it was nice
that Velleman support tried to solve my IC problem.

i have found the fault. it’s not in the IC(in my head perhaps)
there was an extra command (SetAllAnalog) in one of my programs that i was not aware of.
it followed from an another vbs script when i was making copy-paste into the program that i was working
with.

6

OK - It’s good to see that the problem has been resolved!
Indeed, SetAllAnalog will force all the analog outputs “high”.