Are these scavenged parts good for a ZVS? / High Voltage / Forums

Forums

4hv.org :: Forums :: High Voltage

« Previous topic | Next topic »

Are these scavenged parts good for a ZVS?

1 2 3 next

Move Thread

LAN_403

HM_Murdock

Wed Aug 18 2010, 02:21AM

Registered Member #3075 Joined: Fri Aug 06 2010, 02:44PM
Location: Athens, GA
Posts: 148

I am planning to build a ZVS next, and I have a few parts here that may work (please advise)

Cap - MKP-X2, says 250V, 275V, and also says 1.0 uF K on top.I realize it's over-rated, but is that good, bad, or indifferent in this application?

================================================ ==========

The Radial Inductors...have three of them. No clue how to rate them.

Little blue one says 3138 128 70461 LITAI
Short gray says 71731 203K TDK TXM
taller rook looking one says 71371 9920 TDK TXM

================================================ ==========

For the FET's...It's the IRF640A. Found the ratings on these, and they seem small for the design. If I stay under 24V could these work? I have quite a few on hand. .

Here's the link to the PDF
]irf640.pdf[/file]

And a pic (and some gnarly dust bunnies coming after it...)

================================================ ==============

Also, here's the pile 'o parts so far...let me know if you see something there that would be useful in this (or a relevant) project,

william L

Wed Aug 18 2010, 02:34AM

Registered Member #3093 Joined: Mon Aug 09 2010, 11:40PM
Location:
Posts: 68

With A 1uF cap, I suggest using a lower amount of turns. However, this means you will need a big inductor to limit the current. (I don't recommend those ones you have) And keep the Irfp640's on a heatsink. With that said, It will probably work. Good luck!

HM_Murdock

Wed Aug 18 2010, 01:18PM

Registered Member #3075 Joined: Fri Aug 06 2010, 02:44PM
Location: Athens, GA
Posts: 148

I don't mind using a different cap or inductor...the transistors are the more major concern (as they will be the most expensive to replace).

If I replace the other parts with new parts to spec, will those IRFP640's hold up on a CPU heatsink/fan, or will they be fried?

EDIT -

Here's the shopping list I have made (this includes the transistors in case mine will not work). If someone with experience would verify these so I am not tossing $ away, I would appreciate it

1 M8885-ND INDUCTOR TORD HI AMP 47UH VERT
6 1N5349BGOS-ND DIODE ZENER 12V 5W AXIAL
6 497-3243-1-ND DIODE ULTRA FAST 600V 1A DO-41
6 RSMF3JT470RCT-ND RES MO 3W 470 OHM 5% AXIAL
6 P10KW-3BK-ND RES 10K OHM 3W 5% METAL OXIDE
2 IRFP250N-ND MOSFET N-CH 200V 30A TO-247AC
2 495-3589-ND CAP 68000PF 1000V METAL POLYPRO

cjk2

Wed Aug 18 2010, 02:53PM

Registered Member #51 Joined: Thu Feb 09 2006, 04:17AM
Location:
Posts: 263

None of those parts are linked correctly.

Plasmana

Wed Aug 18 2010, 03:04PM

Registered Member #3108 Joined: Thu Aug 12 2010, 05:37PM
Location: Worthing, England
Posts: 72

One of my ZVS driver uses cheep IRF540 MOSFET's and they work just as well as my other ZVS driver using more expensive MOSFET's.

So I imagine IRF640 should work well too, however, it may get warm due to the fact it can handle max 9A, I would put a heatsink on them. And make sure the MOSFET's tabs are isolated from one another if they are sharing the same heatsink!

EDIT:
The inductor you listed is a tad bit pricey (personaly)

Just an option but you can take one of the largest bobblin inductor you have in your collection, take the original windings off and wind on 20 turns of 18 AWG (or similar) magnet wire. That should do nicely for your ZVS driver.

HM_Murdock

Wed Aug 18 2010, 03:14PM

Registered Member #3075 Joined: Fri Aug 06 2010, 02:44PM
Location: Athens, GA
Posts: 148

Thanks for the replies Gents...

Links to parts should be working now...was using Digikey's link from my search directly to the part. They now point to the part name results.

radiotech

Wed Aug 18 2010, 03:50PM

Registered Member #2463 Joined: Wed Nov 11 2009, 03:49AM
Location:
Posts: 1546

The 1.0 uFd capacicitor is a polypropylene snubber capacitor.
which will leave a long lingering smell if you melt it down with to much high frequency current.

Is that discoloration on the case ? Kinda looks a perished compact fluorescent lamp.

HM_Murdock

Wed Aug 18 2010, 05:08PM

Registered Member #3075 Joined: Fri Aug 06 2010, 02:44PM
Location: Athens, GA
Posts: 148

Plasmana, thanks for the feedback...was wondering if I could make one of those inductors work...

radiotech, that cap is from a Dell 17" monitor. Was working when it was unplugged, but that was a couple of years ago.

EDIT - finally found an electric motor repair shop nearby who stocks magnet wire of all sizes. They said I can buy what I need from them in small quantities by weight. Will get some 18AWG for the inductor...what is the optimal AWG for the ZVS primary coils?

radiotech

Wed Aug 18 2010, 05:33PM

Registered Member #2463 Joined: Wed Nov 11 2009, 03:49AM
Location:
Posts: 1546

Give these folks a call

quicksilver

Wed Aug 18 2010, 05:35PM

Registered Member #1408 Joined: Fri Mar 21 2008, 03:49PM
Location: Oracle, AZ
Posts: 679

For wire - look at voice coils in old speakers, motors / alternators, CRT TV & monitors, etc. You won't need miles of it. However, there was a young guy who found a type of alternator or motor of some type that allowed enough wire to come off to make a secondary coil for a Tesla Coil - so it CAN be done quite well IF you hunt. To defeat a great amount of varnish without destroying the insulation, a hairdryer and get that warm enough to unwind without solvents (occasionally - sometimes it's ridiculous).
I have also done what Plasmana did and put together ZVS drivers with lightweight transistors (they functioned w/ a decent heat-sink but they got warm. With all the correct parts there was virtually no warmth at 30v 15a).

Of course, just an opinion, but if you get in the habit of collecting parts most of this hobby costs VERY little. The tough parts are the PROPER caps (especially for a TC), HV diodes, & tubes (if you're so inclined). MOST other parts can be scavenged. Occasionally IF you have storage space you can pull them when you need them. OR there are methods to pull a lot at one stroke.
A light touch and some hemostats / alligator clips as heats sinks will allow you to take a butane torch or similar to the back of a PC board and use a hemostat to pull many parts at a time. Transistors and diodes could use that heat sink but a light touch can get them all off fast.

1 2 3 next

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob