Old timer conversion.

[TinMan]

Hi Guys
I have this old test oscillator that i would like to turn into a square wave generator with high current output if needed.
If anyone knows of an easy way to do this,the info would be much appreciated.
Here is a video description of the old girl.
http://www.youtube.com/watch?v=OShpT5PGrzA

[muDped]

What sort of current are you wanting in the
square waveshape?

High speed switching at those frequencies of
your generator is possible but would require
some really exotic semiconductors and
circuitry.  Maintaining a square waveshape
over a broad frequency range is exceedingly
difficult at moderate expense.

Your video is interesting as is the signal generator.
The scope display reveals a signal waveshape which
is non-sinusoidal and therefore harmonic rich.

[giantkiller]

Check op-amp comparator circuit into a fet driver. Also there might be fet drivers that you could put the signal generator output directly into.

[BEP]

Before using that signal generator as a basis for higher power square wave output I would repair it.
The current output should be nice clean sine-wave with minimal harmonics. You have the opposite showing on the scope.

Having been through that I suggest looking into function generator modules on Ebay, or similar. You can pick-up an very good FG for less than $20, even as low as $5.

Then build an SSR (solid state relay) from a chip or two and a MosFET as an amplifier.

The time you spend repairing that SG and then building an amplifier isn't worth the cost of buying something else.

Sorry. Like I said, I've been through that. I have a couple of very nice old signal generators but never use them due to a few $20 Ebay'd FG's.

Avoid buying an FG that isn't guaranteed to work. If you do, let me know what the thing is. I should have schematics for it.

-------------

Just checked.......

No Sanwa documentation here 

[TinMan]

Thanks for the info guy's.
Seems like it is easer just to get one from ebay at those prices.
I just have the old thing lying around and thought i might be able to use it for somthing.

Cheers
 

[poynt99]

tinman,

First ask yourself if you really need to go to 300MHz. If not, what is the practical highest frequency you will need?

Also, you would be better off building or buying a square wave generator. A CMOS oscillator will get you to about 13MHz, such as the one I designed (attached). You could take that and trim it down to what you need in terms of features.

What sort of drive capability were you hoping for?

If you want something a little more sophisticated with adjustable pulse outputs as well the square waves, check the attached TP900 design.

You may also benefit by looking into DDS function generators.

.99

[TinMan]

tinman,

First ask yourself if you really need to go to 300MHz. If not, what is the practical highest frequency you will need?

Also, you would be better off building or buying a square wave generator. A CMOS oscillator will get you to about 13MHz, such as the one I designed (attached). You could take that and trim it down to what you need in terms of features.

What sort of drive capability were you hoping for?

If you want something a little more sophisticated with adjustable pulse outputs as well the square waves, check the attached TP900 design.

You may also benefit by looking into DDS function generators.

.99

Hi .99

I would never need a 300MHz signal i dont think,but it was more that it is just sitting there doing nothing.
So i thought some one may have some sort of circuit that i could make and make use of the old girl.
As it is,i dont see myself ever being able to use it for anything.

I have found a couple of FG's for around $100.oo,so i might just go with one of them.
I checked out your two circuit's-they are very nice,but without a PCB i think i would end up with a big mess.

Thanks for the input,much appreciated

Brad