Looking for a very precise PWM

[Carlos Galvis]

Hello all! i'm running a colloidal silver generator with polarity switch at 1Khz, and i have determined that the duty cycle is absolutely critical. if duty cycle is 50.01% that means that at 1Khz, one silver bar conducts the positive terminal about 0.0001 seconds MORE than the negative at each cycle, at 1Khz thats 1000hz * 0.0001 = 0.1 seconds of difference between one bar and the other EVERY SECOND. That does't seem like much, but if you wait for 10 minutes = 600 seconds, you get 600*0.1= 60 seconds. these numbers are not exact, just an aprox, so around one full minute that the positive spends on one bar more than on the other for every 10 minutes. After one hour, one of the bars is completely black and the other is light grey, almost intact. so you see the importance of having a 50.000% duty cycle PMW to generate an even formation of oxides between the bars, this results on a much cleaner batch.

Also, i'd like to ask whoever knows, higher frequencies seem to produce less oxides at the same rate of colloidal silver generation than lower freqs. any comments? the duty cycle's exactness is less important at lower frequencies, so if high freqs is required, duty cycle is CRITICAL, thanks for your time.

have a good day everyone

carlos

[John_Koorn]

Hi Carlos,

I would go for the SG3525. It will run the frequencies you're after, the duty cycle is 50/50 and it also has adjustable dead time. So, if needed, you could adjust the duty cycle to say, 49/49 with 1% dead time on each phase. This will allow you to prevent cross over due to device switching times.

There's also plenty of tutorials online that will help you set it up the way you want it.

John K.