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jdub1581hv

Sun Jul 12 2015, 10:05PM

Registered Member #55219 Joined: Tue Jun 09 2015, 11:21PM
Location:
Posts: 80

Hello all I'm new to the forum and appreciate it(forum) and all of you. The invaluable information and experience is awesome and again thanks for being around!
Apologies up front for long post...

Quick intro:
I have roughly 15years of Carpentry and General construction experience, specialize in Tile and Stone work, and am a complete tech junkie

.
In my years of construction I have had to do quite a bit of electrical work, ie: Panel(sub) work, and standard outlet, switch, and appliances.
I recently within the last 2 years started to teach myself electronics/programming. Have modded several devices such as xbox controllers(led's, rapid fire etc), Tablets (simple mic in jacks, oscope probes(diy) with the intent to have a wireless remote/testing device via bluetooth or wifi. So I am fairly familiar with how circuitry works, though many things still beyond my experience.
So to sum it up, I enjoy challenges to the mind and working with my hands ... So why not build a TC .. :D

I currently have 6 small coils,

1 micro wound approx 400t #40 on a plastic thread bobbin dia: 3cm - height: 4cm -- primary 6t #18 solid tight helical.

1 mini-mini 500t #36 on M&M-Mini container/tube with 4t primary #18 stranded

2 mini with 700+ t #33 (20 - 27 cm tall - 3.25cm dia & 2.7cm dia) with different primaries: 4turn flat spiral / wide helical / or conical #12 thhn stranded

1 mini 2k turns #40 plastic vacuum attachment found on the street (I don't know why either) 3.25dia 20cm tall 3 different primaries: 1)20t bifilar - 7cm dia #18 solid - 2) 20t tight wound #18 solid - 3) 16t bifilar flat coil (shared among all) 1/2 #12thhn other 1/2 1/4" copper tubing for tapping at different locations

1 mini fatty 750t #40 wound on plastic container about the size of a coffee mug dimensions are cubic 7.5cm dia, 7.5cm tall, and 750turns - primary 6t #12 thhn stranded tight or large flat bifilar.

I have been using the basic slayer exciter circuit 4 paralleled 2n3055 with secondary lv end providing feedback to the base. I can get some ok performance for an exciter, but I would like to be able to have it break out with more than a 1cm arc. Power supply is a 22v 75va transformer with a full wave doubler for 32v out 2 +amp?

I believe most all should be able to produce 3-4" sparks .. perhaps not with that transformer, I also have a mot rewired for 36v (haven't used yet because it hums quite a bit secondary is wound as tight as possible.. had to clamp it together) that I will move on to for the higher current capacity.

I salvage most of my supplies form tv's and other electronics. I have a pretty good amount of power mfets for some atx supplies i found on craigslist .. 6 matching (3 pair) 900v enhancement mode NPN's, 6 matching SD20N60 mfets, as well as about 8 1500v HOT NPN's from the tv's.

I also collected all the smps controllers and have 3 of these Drivers.
I have tried to make a 1/2 bridge with one of the drivers, followed the datasheet and added zeners (tail to ground) where needed to help protect the chip from my higher than 12 supply.. (6v on pwm, 12v on phase/ pwr in). I want to avoid buying any driver chips as they don't teach you a thing... I had those drivers on an old 9800gtx+OC gpu..

When running the circuit, I get 0 output for any of the coils and the highside fet heats up really quickly. My guess is that the driver is not well suited for this purpose? seems powerful enough.

Could any one point me in a good direction for making a driver from discrete components or from a tl494, mc34065 / mc34067(HIGH PERFORMANCE ZERO VOLTAGE SWITCH RESONANT MODE CONTROLLER) I can sort-of understand the datasheets, I'd like to think the 34067 would be the ideal chip (from broken plasma tv) Opinion on that? advise on how to move forward from the slayer circuit?

Thanks in advance!

Not the current slayer driver in the pic..

zzz_julian_zzz

Mon Jul 13 2015, 02:22AM

Registered Member #3964 Joined: Thu Jun 23 2011, 03:23AM
Location: Valenzuela City
Posts: 332

Hi,

Welcome, this one

uses TL494 (PWM CHIP). Goodluck SSTC-ing!

jdub1581hv

Wed Jul 22 2015, 02:15PM

Registered Member #55219 Joined: Tue Jun 09 2015, 11:21PM
Location:
Posts: 80

Thanks, I had seen that in the past.. I went ahead and built a similar one (tl494 pwm) to drive a 1/2 bridge.
I wrapped a 16t trifilar ferrite toroid for my gdt. Though it's hard to see it's output without an Oscope..
Also blew my driver chip in the process .. lol..
I guess I should rephrase the question as "How to make a proper Mosfet driver from discrete parts?"

I started playing with my Slayer circuit a bit more, and used JavaTC to help get my approx values.
In doing so I was able to get a (in my opinion) pretty decent breakout.. About 1" in diameter and very bushy like a ball.
Picture did not capture everything (should have had the lights out)

This is my current slayer setup:
2- TIP3055 paralleled
Top load is 2 hdd platters

1437574474 55219 FT172129 20150721 012639 Richtonehdr

zzz_julian_zzz

Fri Jul 24 2015, 08:26AM

Registered Member #3964 Joined: Thu Jun 23 2011, 03:23AM
Location: Valenzuela City
Posts: 332

hi,

A friend gave this circuit to me a long time ago, I've used it on my SSTCs and DRSSTCs before. Worked well until I used this on a 400kHz range drive with 10ms ON times, the level shifter stage (i.e. mosfet with pull up 1k resistor) can't keep up(slow rise times).. I tried to reduce the resistor to 220 ohms, improves it but I decided to use driving chip (only to replace the level shifting stage), and stay with the PUSH-PULL MOSFET drive on the output.

zzz_julian_zzz

Fri Jul 24 2015, 08:29AM

Registered Member #3964 Joined: Thu Jun 23 2011, 03:23AM
Location: Valenzuela City
Posts: 332

zzz_julian_zzz wrote ...

hi,

A friend gave this circuit to me a long time ago, I've used it on my SSTCs and DRSSTCs before. Worked well until I used this on a 400kHz range drive with 10ms ON times, the level shifter stage (i.e. mosfet with pull up 1k resistor) can't keep up(slow rise times).. I tried to reduce the resistor to 220 ohms, improves it but I decided to use driving chip (only to replace the level shifting stage), and stay with the PUSH-PULL MOSFET drive on the output.

PS, cool topload! :D -

-oops wrong button. sorry to admin.

jdub1581hv

Fri Jul 24 2015, 11:21PM

Registered Member #55219 Joined: Tue Jun 09 2015, 11:21PM
Location:
Posts: 80

Right on appreciate it.
Yeah, the breakout is a glass Biker Pig bead my step-mom made for me.. lol

Well Here is what I'm trying to drive (image)

The transistors are marked SD20N60 and Infineon is the maker I believe (lowercase "i" within a circle-ish shape), Many google searches later I still cannot find exactly what they are, either 600v 20a power MFET, or 600v 40a IGBT
They came off of a plasma tv psu (I figured I'd keep the pcb section with the resistors and diodes, just looking to drive them without smoke).

I'd like to think they are IGBT's, but as I said cannot get an exact match even off the Infineon website.
Typing 20N60 in the search gave options for IGBT and MFet sooo...

On the PCB they are setup in parallel (respective pins tied together) though each has it's own gate resistors, also a 600v super fast diode pair on the end.

IF the datasheet I found is for these, the RDS is 0.45ohm, and PD 370w , which seems ideal from what I can understand.
Best part is they were free off Craigslist, but still want to keep em alive as I just popped my Slayer circuit :(

1437779198 55219 FT172129 20150724 155422 Richtonehdr

jdub1581hv

Fri Jul 24 2015, 11:30PM

Registered Member #55219 Joined: Tue Jun 09 2015, 11:21PM
Location:
Posts: 80

My coils are all tabletop as you can see and Javatc put me at around 1.7mhz (average) so not sure if that would work if you had trouble at 400khz.

Justin

Sat Jul 25 2015, 05:45AM

Registered Member #46164 Joined: Wed May 07 2014, 08:16AM
Location: California, USA
Posts: 89

Try to build a secondary with a lower resonant frequency, it should make things easier.

jdub1581hv

Sat Jul 25 2015, 10:25PM

Registered Member #55219 Joined: Tue Jun 09 2015, 11:21PM
Location:
Posts: 80

Halfdead wrote ...

Try to build a secondary with a lower resonant frequency, it should make things easier.

I wholeheartedly agree!

However, until I have a better working knowledge of TC'c and their circuitry I have opted to spend 0 money
thus limited to the usable magnet wires that I salvage (non dipped transformers, degauss wire from tv's etc).

Same for the transistors and other items, except for resistors and electrolytic caps.

So when I get there, I plan to make a 3-5"dia resonator with 30-33awg wire.

Perezx

Mon Aug 03 2015, 10:22AM

Registered Member #54263 Joined: Thu Jan 15 2015, 09:54AM
Location: Perth
Posts: 35

1. Do not use TOO much parelleled transistors. The overall capacitance increases and overall system works worse. Better try something like irfp260...irfp460
2. Try adding film capacitors like 1..10nf to the Source-Drain of FETs (C-E jf bipolars), thus you will get closer to Class E
3. Use of interrupter will make you able to switch to higher voltages without overheating. The simplest interrupter is halfwave rectifier :)

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