On Sun, 22 Jan 2006 14:55:33 -0500, Scott in Baltimore
wrote in
:

+No. I may be dumping these transformers.
+
+

*****

If they have enough current rating, they maybe usefull for a 40VDC
supply to power a 100 to 250 watt amp?

After I made a dimmer using some of these transistors, I realized I had created
a high current DC amp, so I applied half voltage (bias) and fed a capacitor coupled
AC input to the base and took a capacitor coupled AC output from the emitter
and now I can amplify audio. I made a duplicate of the first, and now I have
a stereo class A audio amp. I might take those transformers and create an unregulated
40+ volts DC to power this amp. I need to redesign the input circuit...


Just put a small variac on the line side. You can pick up one on ebay
for peanuts. In fact, I've got a Staco 501 that I'll sell you for $20
plus shipping.


snip
Can I make class AB by making splitters on toroids like is done for RF amps?
I only have large NPN transistors. I've got a lot of them, and quite a few
old computer power supplies for resistors and capacitors.


Yes, the transformer-coupled push-pull audio amp is a fundamental
circuit. The only issue is that an output transformer is required
which limits the fidelity of the amp. That, and you'll probably have
to wind your own output transformer. You could also try a totem-pole
variation -- you need an input transformer with two secondaries (or
some other way of floating the base bias supply), and a really big
capacitor instead of an output transformer. If you use a bipolar
supply you might even be able to eliminate the capacitor.








----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----