oscillator circuit

[giannisasp]

Hi! I need to make a circuit that can generate a square wave and then amplify it up to +/-20V. The output should be between 1 and 2 Hz.

I was thinking of using this circuit and then add an inverting amplifier to adjust the gain but I'm not sure if it will work at such low frequency.

If you have any suggestions...
Thanx!

 

[Roff]

How much current does this +/- 20 volt square wave need to supply, i.e., what's the load?

 

[tsoupl]

take to have
Description: 10 Hz to 10 Khz VCO with square and Triangle Wave Outputs
(Reprinted with permission from Popular Electronics, Fact Card 263. Copyright Gernsback Publications, Inc.) From figure GE94-7 of Encyclopedia of Electronic Circuits on CD-ROM Vol. 1.

 

[tsoupl]

and if u want more help visit this site https://commlinx.com.au/schematics.htm
it will be very helpfull

 

[giannisasp]

I will use it on small electrochromic glass samples for electrical characterisation, not much current is needed, about 0.5A or less.

I used a simulation program to check it and it seemed to be working but i had truble with the ampitude adjustment of the output, the output was at +/-20V while the supply of the opamps was about 15V! and i don't think that's possible so something must be wrong :? .

 

[Roff]

You'll need a high voltage, high current op amp, such as an audio power amplifier. Take a look at **broken link removed**. I haven't used it, but it looks like it should work. You will still need to generate a low voltage square wave to feed it. The first thing that comes to mind is a CMOS 555, either running off symmetrical +/- supplies, or off a single supply with an offset summed into the summing node of the op amp. If you need help with that, post your questions here.

 

[giannisasp]

Looks like a good idea. I'll give it a try.
Thanx for the help...