Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: okguitarman on May 23, 2016, 06:46:16 pm

Title: Hybrid SS/Tube Bridge Full Wave Rectifier?
Post by: okguitarman on May 23, 2016, 06:46:16 pm
 I Have a set of trans. power and output from Backstair HT5, Voltages are (386v red to red no center tap) and (18.4 center tap 18.4)
With Hybrid SS/Tube Bridge Full Wave Rectifier what voltage will I have? With 5Y3
Trying to figure out what amp to build. Amp was push pull 12BH7
I think the output is  22k/8 and 16
Title: Re: Hybrid SS/Tube Bridge Full Wave Rectifier?
Post by: sluckey on May 23, 2016, 07:48:22 pm
Quote
Voltages are (386v red to red no center tap) and (18.4 center tap 18.4). With Hybrid SS/Tube Bridge Full Wave Rectifier what voltage will I have?
With cap input filter, unloaded B+ will be 545VDC. How do you plan to heat the 5Y3?
Title: Re: Hybrid SS/Tube Bridge Full Wave Rectifier?
Post by: okguitarman on May 23, 2016, 08:00:58 pm
Separate tran.
Title: Re: Hybrid SS/Tube Bridge Full Wave Rectifier?
Post by: okguitarman on May 23, 2016, 08:19:34 pm
I think I was over thinking the no center tap that was the voltage I figured.
Hybrid SS/Tube Bridge Full Wave Rectifier was from your page Thank you!
Title: Re: Hybrid SS/Tube Bridge Full Wave Rectifier?
Post by: okguitarman on May 23, 2016, 08:23:59 pm
I tied the 386v to Diode rec. and got 355v
Title: Re: Hybrid SS/Tube Bridge Full Wave Rectifier?
Post by: PRR on May 23, 2016, 08:29:58 pm
> I tied the 386v to Diode rec. and got 355v

Put a capacitor on it.

No cap, you get the Average of a bump-wave. In theory 386 * 0.9 is 347V. Your 386 may be higher no-load, or your meter may mis-interpret a big bump wave. IAC, 347V==355V for any practical purpose.

With cap you get the Peak of the wave. 386 * 1.414 is 545V, what you-all are computing and expecting.

If your load is just a meter, the cap can be 0.5uFd, maybe as small as 0.1uFd, though you surely have some 10 to 100 uFd on hand. Note that 545V is a lot for many caps. e-caps tend to top out at 450V-500V. Film can be bought any voltage but we rarely buy over 400V for routine audio circuits.
Title: Re: Hybrid SS/Tube Bridge Full Wave Rectifier?
Post by: okguitarman on May 23, 2016, 08:34:08 pm
 Ah thank you had me scratching my head! Makes perfect sense
Title: Re: Hybrid SS/Tube Bridge Full Wave Rectifier?
Post by: sluckey on May 23, 2016, 09:24:31 pm
Hybrid SS/Tube Bridge Full Wave Rectifier was from your page Thank you!
Thanks for making me look at that drawing. One of the diodes was drawn backwards. I've corrected it now.
Title: Re: Hybrid SS/Tube Bridge Full Wave Rectifier?
Post by: okguitarman on May 23, 2016, 09:49:54 pm
I am on a mac I wished I had visio
Title: Re: Hybrid SS/Tube Bridge Full Wave Rectifier?
Post by: okguitarman on May 23, 2016, 10:03:52 pm
What could I use that trans. for Maybe a stand alone reverb. Would the voltages work? voltage should drop when loaded.
Just looking for a new project.