Mains synced sstc questions

[costas_p]

Hello to HVF community, I am looking to build a mains synced sstc (here in Greece 230v 50Hz).

I am considering using Kaizer VTTC staccato controller as the AC pulse sensing, so a have some questions:

~ The output that goes into SCR/transistor/mosfet, can it be used in enable pin 3 on UCC3732x drivers? Should I omit R18 (100k) resistor?

~ I am planning to use an ac to dc 12v wall plug adapter for the logic, and a tiny VA rated  230:12v transformer in order to drive the Q1 (2n2222), so R3 resistor and Q1 emitter should be
   connected to the wall plug's dc negative side, or the neutral side of the small transformer? Or maybe for that to work, neutral side of transformer secondary and logic ground should
   be one?

[Mads Barnkob]

You need to have a common ground for it all, else there is no reference between AC to DC side through 2N2222, I can at least not tell you what would happen.

Grounding all power supplies negative and one leg of the secondary side of a isolation transformer is known as PELV ( https://en.wikipedia.org/wiki/Extra-low_voltage#/media/File:Extra_low_voltages_(third_safety_class).JPG ) and that is best practice for electrical safety.

R18 could properly be omitted, you do not need current limiting for driving the UCC gate driver IC.

[dexter]

Hi. Here is my take on mains synced sstc using the same staccato circuit but with a few improvements

I used a single power supply (mains transformer) for both the zero cross detection and to power the controller. To do so you'll need to add a diode in series with the bridge rectifier (note 1)

This circuit will utilize both peaks of the mains sinewave giving you up to a max 100 bps

The phase control pot (Power) when turned to max will either never reach the max 10ms time or will exceed it clipping on the next period resulting in a noticeable drop in BPS. To fix this choose the timing R C a bit over 10ms but add a trimmer in parallel with the pot (note 2)

Edit 1. sorry for the messed up schematic but is the same as Kaizer VTTC staccato
controller
Edit 2. my profile pic is this mains synced sstc running at 100 bps and max power (10ms)

[Magneticitist]

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SciTubeHD's ramped PLL SSTC. He has his staccato output going to the enable pins. Beautifully simplistic overall circuit and results.

[costas_p]

Thanks all for your answers, I am too late because the China pcb with the driver I ordered took ages to arrive.

I eventually used loneoceans r-sstc interrupter.
However, no matter what I do, I am unable to make this sstc start.

I am using a H-bridge of irfp460 and a 1:1:1:1:1 15 turns gdt n30 material, OD around 42mm
Primary is 100mm diameter , 1,5mm2 cable, 10 turns , and turn spacing 2mm. Primary cap is mkt 1,33uF (2x680nF parallel)

As far as I can understand I need to first power the bridge, and after the driver. Up untill 100v from the a variac the coil won't operate. I did the first steps in troubleshooting, reversing primary wires, CT phasing, driver phasing.

The question is the the caps C4 and C7 in the attached schematic need be electrolitics, or ceramic type?

[Landon]

Capacitors C4 and C7 can be electrolytic or ceramic.  I have tested this circuit and it works the same either way.  Besides that, I am not sure why your coil won't start up.  Could you send a picture of your setup?