Page 1 of 1
28V 40A PSU
Posted: Sat Dec 20, 2003 4:50 pm
by Yoda
I recently obtained a 330watt linear FM amp to use with my transmitter. I need to build a 28V psu to run at about 40A in order to power my amp. I have thought of using multiple 2n3055 transistors to regulate the output, but I am finding it hard to find a circuit for the PSU.
Anyone any ideas (or circuits) where I might get a circuit or schematic for the PSU??
Posted: Sat Jan 17, 2004 7:46 am
by Recon Blazer
OH MY GOD!!! I love your account and profile! No, may the Force be with YOU.
WHere do you obtain transmitters?
Posted: Sat Jan 17, 2004 6:34 pm
by pcs
I've seen similar designs in this book:
http://www.amazon.com/exec/obidos/ASIN/ ... spiraterad
This is one of my favourite books, I've probably opened it at least
1000 times for various tips, ideas, theory, practical designs....
Its The Holy Bible of radio electronics.
Re: 28V 40A PSU
Posted: Mon Jan 19, 2004 8:42 am
by Fleetinglimpse
Yoda wrote:I recently obtained a 330watt linear FM amp to use with my transmitter. I need to build a 28V psu to run at about 40A in order to power my amp. I have thought of using multiple 2n3055 transistors to regulate the output, but I am finding it hard to find a circuit for the PSU.
Anyone any ideas (or circuits) where I might get a circuit or schematic for the PSU??
Greetings,
First of all if you need 40AMPS to get 330WATTS out of an RF amp..then you have the most inefficient cct. design available..Any Amp that is available for a 28 Volt feed should never draw more than 10-12 amps maximum..However it is good to have a 40 Amp reserve.
However if you are really interested in learning and not being stupid or wantonly naive ABOUT RF AMPS AND THE MANNER IN WHICH THEY ARE POWERED YOU may wanna go to
http://groups.yahoo.com/group/pirate-ra ... 0RF%20AMPS Where i have preapred a series of articles hopefully that will be of of help to you and others in educateing yourselves...Obviously you seem to know enough to ask a question but one can detect an element of stupidity in the manner in which you have worded or been scripted to word your question.
Respects...Norm B
Posted: Mon Jan 19, 2004 3:36 pm
by pcs
Not entirely so. You need at least 330W, if the efficiency is 100%, which
is 330W/28V = 11.78A
Of course there is no such thing as a 100% efficient amp.
In reality it will be closer to 65% or so. Which means about 18A.
20A power supply should be enough. If you want to play it really safe,
use 25A. Absolutely no need for more amperage.