Search found 24 matches

by simf14
Fri Aug 03, 2007 6:24 am
Forum: General Discussion
Topic: Isolator/Amplifier
Replies: 29
Views: 5885

Here is a less desirable circuit that does have a feedback loop...


Image
by simf14
Wed Aug 01, 2007 6:01 pm
Forum: General Discussion
Topic: Isolator/Amplifier
Replies: 29
Views: 5885

Thank you Hackle and AL, I buy the beer if ever in CA!!!
by simf14
Wed Aug 01, 2007 2:23 am
Forum: General Discussion
Topic: Isolator/Amplifier
Replies: 29
Views: 5885

Sir Al, Is there enough safety margin (isolation) between the DA converter and the rest of the circuit. If the 358 is merely measuring differential in the two input legs can we put higher resistance on both input legs, or even the isolation amplifier we talked about earlier??? That DA converter is $...
by simf14
Tue Jul 31, 2007 9:14 pm
Forum: General Discussion
Topic: Isolator/Amplifier
Replies: 29
Views: 5885

Al your the greatest!

Will give it a try thank you!!!!!!
by simf14
Mon Jul 30, 2007 7:05 am
Forum: General Discussion
Topic: Isolator/Amplifier
Replies: 29
Views: 5885

Al, Robert, Chris, I greatly appreciate your gentlemen's knowledge and help. With my limited experience I can barely solder parts from a schematic. I do need to have maximum isolation in the circuit and need an isolation amp between the DA outputs, Op Amp and ground because the DA is so dang expensi...
by simf14
Sun Jul 29, 2007 8:13 pm
Forum: General Discussion
Topic: Isolator/Amplifier
Replies: 29
Views: 5885

What I am being told is that basically the op amp is being driven too high and having the non-inverting input stuck at 6 volts means the 741 is trying to push lots of current into the base of the transistor when no signal is present from the DAC. Also the 2N2222 is trying to act like a variable resi...
by simf14
Sun Jul 29, 2007 6:47 pm
Forum: General Discussion
Topic: Isolator/Amplifier
Replies: 29
Views: 5885

Thank you Chris Smith

here is the picture I hope.

http://img213.imageshack.us/my.php?imag ... ly2ch8.jpg
by simf14
Sun Jul 29, 2007 4:35 pm
Forum: General Discussion
Topic: Isolator/Amplifier
Replies: 29
Views: 5885

site

what is a good site to copy it to (why don't they allow attachements here like most boards?) I am new to this thing.

thank you
by simf14
Sun Jul 29, 2007 2:10 pm
Forum: General Discussion
Topic: Isolator/Amplifier
Replies: 29
Views: 5885

Isolator/Amplifier

I would really appreciate some help from someone kind with a moment to spare for a ignorant novice. I am designing a circuit that takes a variable 0-5V, 20ma voltage from a D-A converter controlled by my computer called a LabJack and turn it into a proportional 0-8V 2A output to power an hydraulic s...