Comments on: 600W process report

By: Gísli Ófeigsson

Gísli Ófeigsson — Sat, 21 Nov 2009 19:49:32 +0000

Nice pics Benni.

As for the transformer. 55Vac will give you 77Vdc. You will definately need to
remove some of the secondary windings. For instance, 40Vac will give you 56Vdc,
and if you regulate that down to 48Vdc (?) means quite a lot of heat that you need to remove.

Anyway, a very interesting project.

TF3G

By: tf3cy

tf3cy — Fri, 20 Nov 2009 23:55:50 +0000

I will drill the copper spreader tomorrow, will post a picture with scale. Just broke my only working 2mm drill…so as I’m sick, my brother bought some new drills !

By: tf3cy

tf3cy — Fri, 20 Nov 2009 22:07:01 +0000

yee..I decided to have this site in english, try to add to this EB104 forum that is on “google”. I understand the non-regulated regulated thing..

I have a 1200VA transformer now, I’m going to use that as I don’t have any other 1000-1200VA around.. So better use what I have.. secondary is to high, around 55v.

It is scary – I might see if it’s easy to unwind some of the windings on the transformer – that could be a possibility.

Plan is then to add another 600W EB104, then I might look into using a switch mode supply. So if anyone has a good design for me, please share.

By: Gísli Ófeigsson

Gísli Ófeigsson — Fri, 20 Nov 2009 21:18:06 +0000

OK, my mistake, I thought this was a progress report in Icelandic.

What I was suggesting was to use an unregulated PSU for this Amp.

Regulating a PSU, of this size, with many bipolar transistors, is scary
in my opinion.

TF3G

By: dick - k4xu

dick - k4xu — Mon, 16 Nov 2009 21:18:03 +0000

Ben,
When you get the board and set the mounting holes for the board and the transistors, I would like to know the location of the holes on the copper spreader. I am going to lay out a new PCB for different devices but I want the holes to line up so the new board will fit on spreaders made for the EB104. The printed artwork is “not to scale”.
I make transistors that are compatible with MRF150 circuits but are a more rugged design. If you are interested in trying some let me know.
thanks,
Dick

By: Gísli Ófeigsson

Gísli Ófeigsson — Sun, 15 Nov 2009 20:54:51 +0000

“Heatsink for the PSU.” Hmmmm

Hefur þú hugsað út í hvað það myndi einfalda allt ef
þú slepptir því að regulera spennugjafann.

Eg hef séð að fyrir þennan magnara sé góð spenna 44-47VDC, þ.e.a.s.
fyrir minnst IMD. Slíkur spennir væri þá væntanlega ca. 35VAC með afriðli,
þéttum og álagsviðnámi að gefa þér rétta spennu en án þeirrar hitamyndunar
og vandamálum sem fylgja reguleringu re. (Heatsink for the PSU) og yfirspennuvörn.

73 de TF3G