🚀 go-pugleaf

v064mb9k@ubvmsb.cc.buffalo.edu (NEIL GANDLER) writes:
>   I am a sophomore engineering student and have been researching and
>trying to develop a new type of car amplifier that runs cooler and
>the taim was at the power supply. 12v simply is not enough voltage
>to power speakers to large amounts of power unless multiple amps
>and speakers are used. So most manufactuers use mosfet power supplies
>that step up the 12vdc to higher levels by first providing a 60hz
>oscillating signal and using power mosefets to switch the 12v power
>to a step up power transformer which results in a larger square wave ac
>voltage output. This is rectified and the result is a dual polarity
>high voltage dc power supply for power amplifiers. But the mosfets although
>amazing devices have internal resistances that cause them to heat up a lot
>under heavy current loads. So I tried a mechanical method using 2 high
>speed quality relays. The design amazingly worked with little problems,
>like noise from the 60-hz modulated relays, a small amount of magnetic
>intereference which can be solved and slightly warm relays. The only
>major problem I can see is reliabilty. How many cycles can a relay take
>before they burn out, thats the only question. I must do more work and
*----
Congratulations.  You just (re)invented the vibrator.  This was how
car radios worked in the pre-1960's.  An electromagnet vibrator
did the switching.  Coincidentally, I just dumped the last of my
vibrator stock tonight.  I can't imagine needing replacements in
the foreseeable future.  Vibrators were pretty reliable, all things
considered.

--
	Mike Berger
	Department of Statistics, University of Illinois
	AT&TNET     217-244-6067
	Internet    berger@atropa.stat.uiuc.edu