[NJARC] What 'load' resistor in place of the tubes?

[w2wiq1 at juno.com]

HI STEVE:

TO SUBSTITUTE RESISTORS IN PLACE OF THE TUBE USE OHMS LAW FORMULA.

FILAMENT 4 OHMS 10 WATT RESISTOR.
90 VOLT PLATE 6000 OHMS 3 WATT RESISTOR.

BEST 73
WALTER-W2WIQ



---------- Original Message ----------
From: <sgt88 at atlanticbb.net>
To: <njarc at mailman.qth.net>
Subject: [NJARC] What 'load' resistor in place of the tubes?
Date: Tue, 19 Mar 2013 09:06:20 -0400

Just remember
Reply = Poster
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_________________________________________________________
I'm planning on making my battery eliminator - power supply.

In the breadboard stage...I'd like to use load resistor(s) in place of the 
five 201's and 301's in my Stewart Warner 305...so as not to damage them 
when/if I have to make circuit adjustments to get the "6" (really 5 actual 
volt), 45 & 90 VDC set up.

 From what I see, the tube Ip is 3 ma...the filament is 250 ma...making 5 x 
3 ma = 15 ma total Ip....5 x 250 ma = 1.25 A total filament current

Only one tube gets 45 VDC

Thus:
45 VDC needs 45/0.003 = 15k ohms say 1/2 watt
90 VDC needs 90/0.012 =  7.5k ohms  say 2 watt
5   VDC needs = 5/1.25 = 4 ohms  say 10 watt

Would these resistors do the job??

Steve T.



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