Halfbridge IGBT SSTC project to check
Phil33ts, Wed Apr 27 2016, 12:44PMHey
I have made a SSTC project and I'm ready to etch and solder but first I want to ask you if everything is done correctly.
The project goals:
- IGBT halfbridge
- switchable FULLWAVE (filtered 220uF) and HALWAVE modes
- TC442* mosfet drivers for GDT (with tantalum capacitors)
- feedback antenna with 74HC14
- NE555 interrupter (but with a jumper it is possible to connect external interrupter)
Schematics:
Halfbridge:
Supply:
Driver:
PCB:
Any suggestions are welcome, but basically I have such questions:
1. Is my idea for having both Fullwave/Halfwave modes toggled by a switch correct? Please note how are diodes connected and how electrolytic capacitor is blocked with diode.
2. Is the entire schematic ok?
3. Is the PCB layout acceptable and what can I improve there?
Thanks in advance!
Re: Halfbridge IGBT SSTC project to check
hen918, Wed Apr 27 2016, 05:42PM
As an electronic engineer, with no experience with tesla coils:
Why's your electrolytic blocked by the diode? The half-wave rectification has very little filtering. It should have more than the full-wave circuit. This is going to cause nasty high frequency, huge current spikes on your rectifying diode. It will not be happy.
Your half-wave rectifier is also using two diodes, where only one is required, this will cause additional power dissipation.
Wouldn't one non-inverting Schmitt trigger be better than two inverting ones? Like the 74HC7014
?
Experienced coilers may find other potential flaws.
BTW, we seem to be missing one of the layers on the PCB.
hen918, Wed Apr 27 2016, 05:42PM
As an electronic engineer, with no experience with tesla coils:
Why's your electrolytic blocked by the diode? The half-wave rectification has very little filtering. It should have more than the full-wave circuit. This is going to cause nasty high frequency, huge current spikes on your rectifying diode. It will not be happy.
Your half-wave rectifier is also using two diodes, where only one is required, this will cause additional power dissipation.
Wouldn't one non-inverting Schmitt trigger be better than two inverting ones? Like the 74HC7014
? Experienced coilers may find other potential flaws.
BTW, we seem to be missing one of the layers on the PCB.
Re: Halfbridge IGBT SSTC project to check
Phil33ts, Wed Apr 27 2016, 07:27PM
Phil33ts, Wed Apr 27 2016, 07:27PM
hen918 wrote ...
Why's your electrolytic blocked by the diode? The half-wave rectification has very little filtering. It should have more than the full-wave circuit. This is going to cause nasty high frequency, huge current spikes on your rectifying diode. It will not be happy.
Your half-wave rectifier is also using two diodes, where only one is required, this will cause additional power dissipation.
As far as I know the "half wave rectified SSTC" must not have electrolytic capacitors, because the input voltage should be a half of a sine wave, and this will produce a certain spark effects. So I've used two diodes to avoid filtering when using half-wave mode.Why's your electrolytic blocked by the diode? The half-wave rectification has very little filtering. It should have more than the full-wave circuit. This is going to cause nasty high frequency, huge current spikes on your rectifying diode. It will not be happy.
Your half-wave rectifier is also using two diodes, where only one is required, this will cause additional power dissipation.
hen918 wrote ...
Wouldn't one non-inverting Schmitt trigger be better than two inverting ones? Like the 74HC7014 ?
The package is not really smaller, is it?Wouldn't one non-inverting Schmitt trigger be better than two inverting ones? Like the 74HC7014
? hen918 wrote ...
BTW, we seem to be missing one of the layers on the PCB.
No, it is single-sided, so I can manufacture it easily at home.BTW, we seem to be missing one of the layers on the PCB.
Re: Halfbridge IGBT SSTC project to check
hen918, Wed Apr 27 2016, 08:12PM
Just looked up "half wave rectified SSTC" and I see what you mean.
The two diodes I was referring to were D14 and one of the diodes in B2, not the filter diode.
I was referring to the buffer from a signal processing point of view. In my experience, one device doing something is always better than one device doing two things, and then another undoing one of them, and doing the other thing again.
Ahhh, single sided, I thought it was at first but I can't see anything connected to the power supply section.
hen918, Wed Apr 27 2016, 08:12PM
Just looked up "half wave rectified SSTC" and I see what you mean.
The two diodes I was referring to were D14 and one of the diodes in B2, not the filter diode.
I was referring to the buffer from a signal processing point of view. In my experience, one device doing something is always better than one device doing two things, and then another undoing one of them, and doing the other thing again.
Ahhh, single sided, I thought it was at first but I can't see anything connected to the power supply section.
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