RS Project Page 3

More ways to drive IGBT's and MOSFET's. Use Optoisolator's to Isolate the Transistor Hi V Power Supply from the rest of the circuit, as shown in the other posted Schematics.

This experimental circuit should allow everyone to use a Computer Sound Card and Tone Generator software to generate frequency's up to 20KHz or more, to Pulse Width Modulate, any given electrolizer cell bank, at any voltage necessary, to test the lowest possable voltage that will work on that cell bank. Has a optoisolated driver section, so that any Hi voltage on the driver side, will not feed back and fry a soundcard, My sound card will output 30KHz before it does strange things and this circuit likes the Sawtooth wave output vs the Sq wave. Remove the 20 amp power supply circuit, to operate on 12V only.

The AC to DC rectifier OP Amp with the positive polorized diodes in the previouly shown (ScanImage1010.gif) circuit, could be added between the first op amp and the pulse shortner transistor for a more stable operation at higher frequency's if necessary. If one were to add a 3rd opamp, w/ negative polorized Diodes (ScanImage1005.gif) feeding a 4069 or other inverter, that's also driving the pulse shortner transistor Q10, changed to a 2N3906 PNP, one could double the effective Sq wave frequency being fed to the pulse shortner transistor, then to the 555 PWM, because you are now using both the pos going pulse and the neg going pulse to drive the pwm, so that 40-50KHz is with in reach of this setup by doubling a 20-25KHz sound card Sq. wave output signal.......

This experimental circuit should allow everyone to use a 556 PWM, to Pulse Width Modulate , any given electrolizer cell bank, at any voltage necessary, to test the lowest possable voltage that will work on that cell bank. and should work up to 50Khz with a little tweeking of the timing Resistors and Caps . Has a optoisolated driver section, so that any Hi voltage on the driver side, will not feed back and fry things on the PWM side. Remove the 20 amp power supply circuit, to operate on 12V only.

Fully Adjustable, Equal Component Value, 2 Pole State Variable Filter. with a Basic White Noise opamp circuit. For testing narrow bands of frequency's to help keep a box resonating at it's sweet spot. as the temp, and various and other factors change over time, thus shifting the sweet spot as things change........

A Bob Box Design, for a 120VDC Power Supply running through a Modulated Torrid transformer using any 500 watt audio amp to modulate the transformer, the audio amp needs to see 8 ohms impedance on the primary winding.

So I took the Inductance values and DC resistance values for the ITL series listed as shown,

http://wilcocorp.com/catalog/series.cfm?series=ITL

and crunched the numbers, with the impedance formulas for working with the Primary side of this transformer to macth it to a car audio amp so that it looks like a speaker to the amp.....

here is what I came up with,

ITL102 impedance at various frequances

L =1000 uH R =.03 ohms

at 1KHz = .188 ohms

at 10KHz = 1.884 ohms

at 25KHz = 4.71 ohms

at 48.2KHz = 9.081 ohms

The ITL102 would require a high power amp and would work good at the real high freq.'s above 25KHz but might pull too much current at the lower freq's and need to be hi pass freq. limited in some way so it dont see the lower freq's below 10KHz

ITL252 impedance at various frequances

L =2500 uH R =.09 ohms

at 1KHz = 1.413 ohms

at 10KHz = 14.13 ohms

at 25KHz = 35 ohms

at 48.2KHz = 68.107 ohms

a smaller amp would push this and would work better at the lower freq's below 10KHz

So I think eather one of these will take care of the primary side of this transformer depending on what freq's you plan to run through it......

Wind the secondary with what ever works at the 120VDC power supply used.......