OMG it's the 8038 again!!

[Rob11966]

Hi again folks,

The 8038 returns but this time I have 2 promises -

1. This is the last question about the 8038 function generator (see thread with schematic below) and

2. It's a simple one this time

After significant help from the forum my 8038 based function generator works very well. Not being satisfied with this I have added a simple LED frequency counter which I bought off ebay for $18. It's actually not a bad little unit and when powered with an external AC supply (+ simple regulator circuit) it works brilliantly. However, when I tap off the same secondary that I used for the function generator the counter reports incorrect frequencies and it also interferes with the generated waves.

Obviously the simple solution is to drop in a separate transformer and run the counter off this. I can do this but I am looking for a more elegant solution.

Here is the question - Is there a simple way to 'share' the existing secondary winding without cross interference between the function generator and the frequency counter? If there is a simple solution let me know, if not I will just resort to the separate transformer solution.

Cheers,

Rob

[saposoft]

No way to share it , and no cheap way to do it , use a second pwr supply .
Get and advice , shield the freq counter and it's pwr supply very well , optimally use a closed metal box with ceramic passtrough ( look to HAM radio construction ) , without shielding digital noise is for sure getting into the 8038 .
Have fun , the 8038 is a funny little beast i'm using it since it's born and i'm going to use some of the leftover since those days again now...
bye bye
Sapo