|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
97.105.99.138
In Reply to: RE: final report on switching trans vs halo trans for filament supply posted by vinnie2 on January 03, 2017 at 06:34:16
Glad to hear it's working for you.
"Now all I have to do is try and get one of the 60 watt halo units down to 1.5 volts ac and give that a try on the 26's."
After more work on this, I don't think these high step-down ratios will be feasible with the half-bridge circuit. It might be better to gut the oscillator components (except the two switching transistors) and add a daughter board. The added board could use a high speed, differential output device to drive the two transistors. With this approach, frequency could be set using RC components, and the duty-cycle could be adjusted to exactly 50% for ease in setting the RMS voltage. This might also have some benefit in generating the higher filament voltages needed for 211/845/GM70 tubes. I'll post any progress I make with this.
--------------------------
Buy Chinese. Bury freedom.
Follow Ups:
Now you are WAY over my head. No chance of me doing something like that without step by step instructions. I have two of the 60 watt units on the way, and when they get here I will try peeling off some windings and see what happens. Did you actually measure the lowest voltage you got? If so, how many windings were left?
I am interested too for other project
anyways you could count the number of turns divide into the voltage then you will have a good idea how many turns= how much voltage then just unwind until you get what you need i hope this makes sense
Lawrence
Vinnie, it's not as complicated as it probably sounds. I think the minimum voltage possible was 5-6V rms (10-12V pk-pk). Probably four or five turns on the secondary.
--------------------------
Buy Chinese. Bury freedom.
So what happens if you only leave one or two turns on the secondary?
"So what happens if you only leave one or two turns on the secondary?"
It won't oscillate.
--------------------------
Buy Chinese. Bury freedom.
And what does that do to the operation?
If it doesn't oscillate, there's no output.
--------------------------
Buy Chinese. Bury freedom.
That can't be good! : )
well first count how many turns are wound on the core then divide into the specified voltage that they are rated for
so once you have the turns/voltgage/ratio you should be able to understand
you maybe only able to take off some of the winding and make it work correct I have no time with these...suck it and see!
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: