BARACUDA-Legend-1

[TH Jim]

BTW:

Great job ApBerg!! Good work, as always from you!

As you know I thought it was strange to have 2 different FET's, now we can guess why - it doesn't matter as long as they are matched!

Regards, Jim.

[plumabob]

Thanks for trying to help me. Still don't understand it. Like I said this is greek to me, if someone could just point out which 2 fets should be the same I would appreciate it.

Bob

[DIRCEU]

Hi! All


If you use 4066 instead the fets, like Surfmaster, then...

Dirceu

[mikebg]

Thanks for trying to help me. Still don't understand it. Like I said this is greek to me, if someone could just point out which 2 fets should be the same I would appreciate it.
Bob

Bob, I agree with DIRCEU that you can use 4066 because Q3 and Q4 operate as analog switches. In this case the most important parameter is Rds_on.
The parameter can be measured with an ohmmeter as shown below.

[habitbraker]

...But then sample pulse pulse polarity must be changed

[mikebg]

...But then sample pulse pulse polarity must be changed

The analog switch should operate with both polarities. What is the funny?

[Vortxrex]

Should add FET Sockets

Should add some simple 3 pin sockets in place of the FETS so you can experiment with FETs to find a good match.

Dave Frank

[habitbraker]

The analog switch should operate with both polarities. What is the funny?

oh yes of course - you always can connect negative supply to VSS and 0V to VDD.
Why funny?

[Alexismex]

Thanks Apberg for this real discover ...if i remember many years ago Eric Foster tell that he match the fets in their circuit ...but nobody react in the forum ... and now it is a good notice for us ....
For the 4066 i have many times compared with the single fet in particular the J113 and for my appreciation it is much better the fet configuration J113
Thanks again

[plumabob]

PLEASE can somebody show me which 2 fets should be matched???? I don't want to cook my one and only board.

Thanks

Bob

[maikl]

PLEASE can somebody show me which 2 fets should be matched???? I don't want to cook my one and only board.

Thanks

Bob

There is talk of Q3 and Q4.

[plumabob]

Thanks, Maikl! Now i got it!

Bob

[6666]

AP
just for interest would you mind telling me the exact part number on U2 and U4
that you used in your Bara please

thanks

[ApBerg]

AP
just for interest would you mind telling me the exact part number on U2 and U4
that you used in your Bara please

thanks

Hello

For U2 I used NE5534 and for U4 the LM358 ....

Best regards.

Ap

[6666]

Hi AP
thanks

sorry for my poorly worded question
what I was trying to ask was
what are the complete numbers on the chips
for example ne5534XYZ
and LM358XYZ

thanks
cheers