LinkBack Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
  #22   Report Post  
Old September 10th 08, 06:02 PM posted to rec.radio.amateur.homebrew
external usenet poster
 
First recorded activity by RadioBanter: Jul 2008
Posts: 242
Default microwave oven inverter P.S. revisited

On Sep 9, 7:50 pm, Grumpy The Mule wrote:
Ok, this should work. http://tinyurl.com/6at4zu

I mean the primary of this thing uses litz wire that looks like 10AWG
wire about 13 turns around the core
and they using 4 strands of 28 AWG to run the filament
The HV secondary measures only 6.8 ohms DC.


I'm glad you mentioned that. If the core is ferrite and it's gapped,
then the litz makes sense to reduce eddy current losses from the
fringing field sprayed out of the gap. A gapped core would also most
likely mean it is a flyback.

It really is amazing the power density SMPS can achieve. Though the
overload capacity available from big hunks of iron and copper isn't
to be discounted lightly. I had to pick up a 10KW autotransformer
today. I don't know how much it weighed but I'd guess 130lbs, or
there about. The two transformers in the 10KW SMPS are maybe four
pounds total.


Hey mule

Exactly right it is a gapped core. Once I git's a scope on I'll see.

But the voltage doubler they using is full wave doubler. Which means
they taking the positive and negative waves to get 4000 or so volts
DC
Now the positive half they use a .0082 mfd for a filter and the
negative half they use a .0056 mfd filter both at 3000wvdc.
..
They use a damper diode that looks like a varistor, and a hold down
cap is .032 mfd at 500V across the primary.
The power into the primary is filter by an LC just to prevent the RF
getting back into the mains/bridge diodes pack.

73 OM

n8zu

 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Microwave oven transformers. terry Homebrew 6 November 4th 07 07:59 AM
microwave oven power supply Jimmie D Homebrew 28 August 12th 07 01:32 AM
Microwave oven transformers AndyS Homebrew 13 July 29th 06 10:53 PM
Microwave oven magnetron Frank Antenna 5 June 14th 05 12:50 AM
EM field og GSM and microwave oven in V/m ? Thierry Antenna 3 November 9th 04 04:57 PM


All times are GMT +1. The time now is 05:40 PM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004-2025 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017