Oops, really meant (55*.08)W = 4.4W; probably use a 10W WW resistor. I
can't read my own typing, that's pretty sad...and it's only Friday -WB2WIK/6
-----Original Message-----
From: Steve Katz
Sent: Friday, January 07, 2005 3:34 PM
To: 'carl seyersdahl'; Amps@contesting.com
Subject: RE: [BULK] - [Amps] regulators
I'm slowly getting back to my first priority (love?) my revamped SB201/
SB200.!!! I'm wanting ? ( no, AM using , Rich's QSK setup. Since the SB200
has a 110 v ac winding on the xfmr I will use that for the DC voltage for
the unit. However, I am thinking about a shunt regulator to hold the DC for
that ckt to 100 VDC.Most of the zeners I've looked at are around 36 v.
(mol), so I thought to use 4 ea. 25 v units in series, to gnd. But I've long
ago forgotten how to figure the reg current needed to hold a good regulation
on a ckt.(in this case 80 ma. )
::For 80ma through the regulators and a 110vrms AC source, assuming you'll
rectify that with a bridge/capacitor and create about 155Vdc, your resistor
needs to be E/I, or (155-100)/.08 = 687.5 Ohms at (100*.08)W = 8W. I'd use
~650 to 750 Ohms, 15W WW. Throwing away a bit of power this way, but if
that's what you want...what's the purpose of the 100Vdc? -WB2WIK/6
Also the formulas for figuring the resistance values for the regulator
ckt.
It should also be noted here that I've given away most of my books (to the
next generation) so I have little to fall back on .!!!!!
If there is any help out there I'd appreciate it.!!!
thanks to all!!!!!
carl / kz5ca
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