Hi steve
OK i am looking at my circuit again now testing the power supply to the 4093 shift oscillator .
I am using a switchable voltage power pack..... results are when the circuit is on 6 volts the shift oscillator runs higher 42 khz on 12 volts it drops to 30 khz ....interesting .
So i am in range here ,as the voltage is raised the frequency drops the amplitude of the squaure wave increases pretty much to what the voltage is to the circuit ...the pf capacitors that turn it into a triangle wave at 30khz this drops the amplitude to about 2 volts/
There is slight spiking to the square wave but i don't see a problem on the triangle wave after .
So to me it looks ok ....
i am useing a cd4093be for the shift oscillator and i have grounded all unused inputs as jeremy recommended.
If you think this looks ok also i can move onto the opamp ....i am using a ua386pc i am not sure if there is a difference to the recommended Lm348 ?
I have run out of time today to do any more testing but i will look into the video if its inverted or not .
i did notice when using the Black Level control depending on the settings the video will raise or lower in polarity position to the setting of the trimmer more positive or more negative but as i said for some reason i get not pwm out of the 4093 unless its centered ...still need to look for mistakes some where else ,i will try and do more testing after work tomorrow .
I will try and show also next pwm out of the 4093...that should look less messy with it added to the sawtooth in the post above.
It's odd that Jeremy has drawn the NAND gates (both versions) as NOR gates, that confuses me sometimes. As I understand things the sketch below is correct for both standard and Schmitt versions.
OH ! i would be worried if he had not said what the ics were ...
Thanks for the help there i'll do those tests .
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.