On Tue, 02 Oct 2012 21:20:47 -0700, John Larkin
wrote:
On Tue, 02 Oct 2012 21:11:23 -0700, Jim Thompson
wrote:
On Tue, 02 Oct 2012 20:31:25 -0700, John Larkin
wrote:
On Tue, 02 Oct 2012 17:50:14 -0700, Jim Thompson
wrote:
On Thu, 27 Sep 2012 12:44:00 -0700, Jim Thompson
wrote:
AC Cap Dropper DC Power Supply
Anyone know of a clever way to regulate other than the typical
brute-force zener clamp?
...Jim Thompson
I ended up with this...
http://www.analog-innovations.com/SE...00056_MOD3.pdf
Using a depletion-mode NMOS FET.
I have a version I personally liked better that used a cheapy TRIAC
under DDROP3, but I could not find a way to get some "free" power for
the gate... needed while pumping, goes away when overcome by the
switcher coming on line.
(This is a wild high PFC, high efficiency dude, where the customer is
squeezing me for milliwatts :-)
...Jim Thompson
That's crazy. Not only is it expensive, once the 24 volt supply kicks
in, it dissipates most of a watt, doing nothing.
Boy, did I just save you some embarassment.
You're so ignorant you don't know how it works. Thanks for the
exhibition!
...Jim Thompson
Well, how much power do R1, R2, the TL431, and ROFF dissipate once the
main supply is up?
Harder question: what's the worst-case dissipation of the fet if the
main supply doesn't come up, like if the load is shorted or something?
Bwahahahahaha! You lost the thread... actually two threads... and a
controller chip...
Follow your own advice... do your own searching ;-)
...Jim Thompson
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