[Patrick Turner]

On Feb 13, 7:51*pm, flipper wrote:
On Sun, 13 Feb 2011 00:07:31 -0800, Big Bad Bob





wrote:
On 02/07/11 22:03, Patrick Turner so witilly quipped:
Maybe one day during my next lifetime when I return after re-
incarnation from this life I will R&D a SMPS which is acceptably
rugged and effective and cheap.

Don't hold your breath.

more fun, use tubes

I think that the power pentodes that were used in horizontal flyback
circuits might do well enough. *The current ratings are generally high,
even at relatively low plate voltages, and of course they tolerate very
high plate voltages as well. *It's sorta needed for a flyback to work.
It also seems like something you'd want for a switching PS. *A 'flyback
effect' might even work for the switch, provided that there's an
isolation toroid (similar to solid state switchers). *Not sure how many
tubes it would take, but it would be a fun project.

It's self defeating. To get significant current at low B+ takes
correspondingly higher heater current. On top of that, compared to
modern switchers tubes have astronomically high saturation voltage.
Anything you'd hope to gain would be more than swamped by the added
complexity, size, and power to run it.

The 'tube' version of an SMPS is a vibrator.- Hide quoted text -

- Show quoted text -

Vibator PS were noisy, but allowed a small tranny, and were OK in a
car with vibrator PSU in the boot. But with SS mosfet devices either
ON or OFF, effciency gets high and it seems not so difficult to make a
square wave oscillator which might run silently at 25kHz, maybe no
need to fancy-smancy add on chips and crap one sees in schematics for
most SMPS.

Patrick Turner.