solid state tesla coil with optocouplers
theju, Sat Mar 21 2009, 06:32PMhi,
i´m temporary building a sstc without a gdt, because i got some optocoupler igbt driver ic´s( typ: HCNW3120)
The pcb with the optocouplers for a halfbridge is already finished:
(5V/div, 0.5µs/div an 4nF gate, no gate resistor an the igbt is directly connectet to the HCNW)
next week i´m gonna etch the oscillator board(based on the HCF4011 for oscillator, interrupter and one for mixing the signals) and 2 BD137/BD138 driver stages for direkt gate drive because the optocouplers have just 2A output and 2,5A pulsed
that´ll be the pcb
i´ve also integrated an interrupter so i can run "CW" and interrupted :D
the secondary is a 11cm diameter tube, 23cm wound with 0,212mm wire
primary will be 15cm diameter 8 windings of 4mm² wire
greets theju
Re: solid state tesla coil with optocouplers
LithiumLord, Sat Mar 21 2009, 09:08PM
Well, don't want to disappoint you, but like I found out on my path of blown silicon, unipolar low-current drive isn't very usefull for IGBTs that, however, aren't very usefull in something without ZCS and with higher operating frequency anyway ;)
Myself I now use bipolar MOSFET driver modules I made off IXDD408 controlled by 6n137 couplers that drive a gate with -8v negative bias.
LithiumLord, Sat Mar 21 2009, 09:08PM
Well, don't want to disappoint you, but like I found out on my path of blown silicon, unipolar low-current drive isn't very usefull for IGBTs that, however, aren't very usefull in something without ZCS and with higher operating frequency anyway ;)
Myself I now use bipolar MOSFET driver modules I made off IXDD408 controlled by 6n137 couplers that drive a gate with -8v negative bias.
Re: solid state tesla coil with optocouplers
theju, Sat Mar 21 2009, 09:22PM
well i desinged the hole thing so that i have a couple of "modules" wich i can combine the stuff the way i need it
if the bd stuff don´t work i´ll test a irf9530/530 driver stage with +/-25V
that should work better and should be able to handle bigger capacities ^^
theju, Sat Mar 21 2009, 09:22PM
well i desinged the hole thing so that i have a couple of "modules" wich i can combine the stuff the way i need it
if the bd stuff don´t work i´ll test a irf9530/530 driver stage with +/-25V
that should work better and should be able to handle bigger capacities ^^
Re: solid state tesla coil with optocouplers
LithiumLord, Sun Mar 22 2009, 12:48PM
Heh, I a bit missed the drive amp part. The BJT drive would work better in the term of amperage (though I use a single driver IC for that one) - but unipolar drive of IGBTs on such a high frequency would make the maximum rating of the device too low and therefore too uneffective for the component cost. Better upgrade the drive section in order to maintain some negative bias now so that you'll exclude any additional failures in the future.
LithiumLord, Sun Mar 22 2009, 12:48PM
Heh, I a bit missed the drive amp part. The BJT drive would work better in the term of amperage (though I use a single driver IC for that one) - but unipolar drive of IGBTs on such a high frequency would make the maximum rating of the device too low and therefore too uneffective for the component cost. Better upgrade the drive section in order to maintain some negative bias now so that you'll exclude any additional failures in the future.
Re: solid state tesla coil with optocouplers
theju, Sun Mar 22 2009, 03:36PM
i think i´m going to use a irf530/9530 driver with +/-25V
that should turn the igbts off fast enough in combination with 4.7-10Ohm gate resistor combined with a 1n5819.
just have to wait 1-2 weeks till i get some money for ordering the mosfets ._.
theju, Sun Mar 22 2009, 03:36PM
i think i´m going to use a irf530/9530 driver with +/-25V
that should turn the igbts off fast enough in combination with 4.7-10Ohm gate resistor combined with a 1n5819.
just have to wait 1-2 weeks till i get some money for ordering the mosfets ._.
Re: solid state tesla coil with optocouplers
101111, Sun Mar 22 2009, 08:23PM
That sounds a little interesting, got a schematic?
101111, Sun Mar 22 2009, 08:23PM
LithiumLord wrote ...
Well, don't want to disappoint you, but like I found out on my path of blown silicon, unipolar low-current drive isn't very usefull for IGBTs that, however, aren't very usefull in something without ZCS and with higher operating frequency anyway ;)
Myself I now use bipolar MOSFET driver modules I made off IXDD408 controlled by 6n137 couplers that drive a gate with -8v negative bias.
Well, don't want to disappoint you, but like I found out on my path of blown silicon, unipolar low-current drive isn't very usefull for IGBTs that, however, aren't very usefull in something without ZCS and with higher operating frequency anyway ;)
Myself I now use bipolar MOSFET driver modules I made off IXDD408 controlled by 6n137 couplers that drive a gate with -8v negative bias.
That sounds a little interesting, got a schematic?
Re: solid state tesla coil with optocouplers
theju, Thu Apr 02 2009, 08:53PM
final found some time to etch an solder the pcbs of the oscillator/interrrupter and the 2 driver.
i decided to use a irf9530/530 for each gate, with +15V and -12V.
that should charge and discharge the gates fast enough :P
the controller pcb
irf drivers
both are at the moment of taking the pics not finished, but atm the oscillator is completed and working just as i wanted :D
theju, Thu Apr 02 2009, 08:53PM
final found some time to etch an solder the pcbs of the oscillator/interrrupter and the 2 driver.
i decided to use a irf9530/530 for each gate, with +15V and -12V.
that should charge and discharge the gates fast enough :P
the controller pcb
irf drivers
both are at the moment of taking the pics not finished, but atm the oscillator is completed and working just as i wanted :D
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