Successful TPU-ECD replication !

[Jdo300]

Jason,

your FET driver circuit has a big error.  The manufacturer's spec sheet shows a test circuit which they use to determine the switching speeds.   They simulate the large FET input capacity by using a 1nF on the driver output.

In the real world, when you use this FET driver, you must remove this 1nF capacitor; the FET gate already has 1nF or 2nF capacity and you don't want to have an additional capacitance in the form of a 1nF capacitor!

As additional comments,

• the 4uF7 capacitor should be labeled tantal
• the 0uF1 capacitor should be marked ceramic
• it should be mentioned that additional parallel ceramic capacitors never hurt.  For example, additional 1nf and 10nF bypass capacitors.

Pay a lot of attention to the polarity of the tantal capacitor, if wrong polarity the tantal will catch fire and turn into a block of carbon.  Quite a spectacle.

Regards, Earl

Hello All,

I'm finally back from my weekend trip and thought I would take the time to draw up the the circuit diagram for my control circuit.

Hi Earl,

Thanks for the heads up about the 1 nF caps on the driver outputs. This is exciting news since the drivers have been working extremely well (achieving 38ns switch-on times), so it should be VERY good without them! I was experiencing some problems at one point where the FETs were not turning off all the way (when loaded) which may have been due to the cap sitting there charged up. I'll also add the labels for the cap types to the circuit diagram. I am currently using small electrolytic caps for the 4.7 uF filter caps so I'll see about getting some tantalum ones to replace them.

Again, thank you for your suggestions .

God Bless,
Jason O

[Jdo300]

@Jason,

Earl is correct: remove the 1 nF condenser on Mosfet's Gate! It will only decrease the pulse rise-time in our case!   If I were you I'll remove the resistor either as it does not need except perhaps for safety rule.

Roberto

Hi Roberto,

I'll definitely do that. I only had the resistor on between the gate and the drain because the FETs were staying stuck on sometimes after I turned off the circuit board. I realized that I do need the resistors on the input lines to the MOSFET drivers though because the function generators I am driving them with don't go to zero immediately after cutting them off though.

God Bless,
Jason O

[Jdo300]

Hello all,

@Darren,

I totally agree with you. The point is, there are a lot of new people....not in electronics...

With 3 synchronised frequencies its muuuuch better and easier to work but if you have such a success as I had then there is no equipment anymore.
I wanted that the people first learn how to mix, whats going on with the current and voltage from the power supply and then synchronise the frequencies.

@Roberto

be careful.

Otto

Hi Otto,

I'm already headed down the harmonic road as well. I have a bunch of 12-bit ripple counter ICs that I am using to make a 12-harmonic frequency divider board. The board is already made but it has some glitches that still need to be worked out before I can use it. (I originally made it to test out Roberto's original TPU setup with the two harmonics locked in). For anyone else interested, the IC is a 74HC4040 and would be a cheap and easy way to make this. My board has three 12-pin dip switches that route any of the 12 harmonics to the three outputs to drive the MOSFETs. I'm not home at the moment, but I'll post a photo of it later.

God Bless,
Jason O

[giantkiller]

I have to post this again.
The Otto - Robero pdf 1.0 states on page 14 under the heading Summarizing:
CC structure width: about 1".

But I see some builds here are 1/2" tubing.

Needs to be clarified.

--giantkiller.

[joe dirt]

http://www.hauntedfrog.com/gt/movies/2007/duckon/SingingTeslaShow.html

thanks for the link, reminds me of a plasma speaker,  on steroids lol

http://www.plasmatweeter.de/

Dirt