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[TCML] help needed! PSSTC



Hello there! 

My name is jason and i am a first time 
coil builder. my partner chris who has built a small coil before had 
used a kit from eastern voltage research to construct an audio modulated coil for a project, and we decided to take it to the next level for a 
project we are both now working on. we are using a design that is also 
from eastern voltage research but the kit we were interested in was no 
longer available because he was having trouble getting the PCB's for 
this particular kit. so we got ahold of the owner and had him send out 
the parts for his plasmasonic 2 kit and decided to try building it 
ourselves. 

We built a 12v power supply w an LM7812 and 
using this to power the low level electronics. this powers a TL494 which seems to be what most are using for this type of circuitry. out of the TL494 we are getting about a 13MHz transient off of the outputs 
of the TL494. this seems to be ok but as the signal then goes through 
the gate drivers, which are TC4422's, this transient gets reflected at 
the pulse and when it turns off. this is where our problem starts 
getting worse! obviously w these transient signals, the A/B h-bridge we 
are using to power our coil is firing the mosfet's at the wrong times. 

Both of us have experience w electronics and are both attending classes at 
UMO for a bachelors in electrical engineering technology, just so you 
have an idea of what skills we may have attained. we are attempting to 
integrate snubber circuitry to the gate driver outputs to reduce the 
noise for a smoother signal, but have not yet used them in any of the 
labs and/or projects we have taken on. 
i have attached the 
schematics that eastern voltage research provided and some pictures of 
our waveforms (1 of the gate driver outputs, and the rest are of the signal at the gate of the 
mosfets) that we hope will spark some interest among the experienced 
coil builders of this forum. i signed up for the mailing list on this 
site and have enjoyed reading, and have learned quite a bit from the 
discussions here. we would appreciate any help that you all would have 
for us rookies.
It seems that through our experiences that 
this snubber circuitry should be placed in the h-bridge from gate to 
drain on all 4 of the mosfet's. i will be trying a number of different 
things, but we would really appreciate any advice! 

(FYI- we are building this prototype mostly on breadboard. the H-Bridge is constructed on PCB that we have soddered.)

Thank you for your time and i look forward to any response.
Jason Hill & Chris Geele
If there are any other pictures of the waveforms or the actual circuitry/breadbord/pcb that are needed i would be happy to post them

I wasn't able to post attachments of schematics or waveforms and the schematics are not available to the public as they are property of eastern voltage research....if you would like to see the schematics or the pictures i have i would be happy to send them to you. i was not aware that i could not use attachments on this mail listing. 

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