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#16 Re: signal generator - 2nd generation

Posted: Mon Dec 06, 2021 11:23 am
by ed
well that was my question really, can I join 0vA and 0vB?

the opamp is a buffer in effect, it's just that I use it for a bit of gain....strictly speaking I don't have to have any gain, but the problem with sig gen version 1 was that it maxed out at 2v RMS and that was the main reason for looking at version 2 with a bit more output....

#17 Re: signal generator - 2nd generation

Posted: Mon Dec 06, 2021 11:55 am
by Nick
ed wrote: Mon Dec 06, 2021 11:23 am well that was my question really, can I join 0vA and 0vB?

the opamp is a buffer in effect, it's just that I use it for a bit of gain....strictly speaking I don't have to have any gain, but the problem with sig gen version 1 was that it maxed out at 2v RMS and that was the main reason for looking at version 2 with a bit more output....
With that isolating DC:DC converter yes, that's why I suggested it or something similar.

#18 Re: signal generator - 2nd generation

Posted: Wed Dec 08, 2021 7:56 pm
by ed
I did a bit of editing today....got a bit of checking to do..but hopefully get some boards back before the postal lockup as I'll be twiddling my thumbs over the holidays while the rest of the famille are en France...
sg-cct.jpg
sg-cct.jpg (205.91 KiB) Viewed 5880 times
the gold pins are actually sockets but they have the same footprint..
sg-3d.jpg
sg-3d.jpg (123.12 KiB) Viewed 5880 times
if it works I'll probably have 4 spare boards if anybody is interested for the price of a stamp.

#19 Re: signal generator - 2nd generation

Posted: Tue Jul 19, 2022 1:00 pm
by ed
I'm mighty impressed...ordered the boards from China on 8th July and these arrived before lunch:
sg4.jpg
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fingers crossed

#20 Re: signal generator - 2nd generation

Posted: Thu Aug 04, 2022 10:14 pm
by ed
It’s been a difficult birth. 4 years with 3 breaks when something has come along to put the project on hold and made it end up in an ice cream tub in the corner of the workroom. Each time I’ve gone back to it I’ve had to start from scratch as I couldn’t remember what I’d done before, and I didn’t understand the previous notes.

A bit disappointed because I realised the super slick rail splitter was only really good with a battery supply so I had to cobble together a normal supply with a transformer…oh waily…c’est la vie.
sg front.jpg
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sg inside.jpg
sg inside.jpg (79.1 KiB) Viewed 5284 times

#21 Re: signal generator - 2nd generation

Posted: Tue Apr 04, 2023 12:11 pm
by ed
lost touch with this project, I think it's waiting for me to sort the square wave output...it's languishing in the pile of unfinished projects.....

meanwhile, as mentioned in response to Ray's post on the little component tester/oscilloscope/sig gen, I had won this on ebay. It's a Leader LAG-26 and seems every bit as good as the old LFM4 and, in the current climate of sig gen prices, I think I got a bargain...£50. I will run the distortion test later...

20k square wave at 1v rms
new toy.jpg
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#22 Re: signal generator - 2nd generation

Posted: Wed Apr 05, 2023 8:54 pm
by Mike H
Nice! Got something virtually identical from when I was with Maplin. Still does the job. :thumbright: