reduce voltage

Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Closed

Thread Rating:

0 Vote(s) - 0 Average
1
2
3
4
5

Linear Mode

reduce voltage

rghines1
Member

Posts: 190
Threads: 8
Joined: Oct 2005
City: Lexington, SC

#10

03-18-2010, 08:13 AM

Agree with Ron saying that those caps should not have blown to begin with. Take some voltage measurements of the power supply again.

Concerning using a resistor to drop voltage. Assuming the average B+ current is approximately 80 milliamps and with a 1000 ohm resistor would drop 80 volts. Wrote earlier 100 ohms but that would only drop 8 volts which is not much. A 1000 ohm resistor would need to be 10 watts.

The resistor solution is not perfect since during warmup the voltage can still surge quite high. Rectifiers tend to warmup first before the other tubes are warm enough to start drawing current.

Find

« Next Oldest | Next Newest »

Thread Closed

Messages In This Thread

reduce voltage - by denver - 03-17-2010, 02:12 PM

Re: reduce voltage - by rghines1 - 03-17-2010, 05:41 PM

Re: reduce voltage - by denver - 03-17-2010, 05:50 PM

Re: reduce voltage - by denver - 03-17-2010, 05:54 PM

Re: reduce voltage - by rghines1 - 03-17-2010, 08:09 PM

Re: reduce voltage - by denver - 03-17-2010, 08:22 PM

Re: reduce voltage - by Ron Ramirez - 03-17-2010, 08:37 PM

Re: reduce voltage - by denver - 03-17-2010, 09:39 PM

Re: reduce voltage - by Carl Travis - 03-17-2010, 09:44 PM

Re: reduce voltage - by rghines1 - 03-18-2010, 08:13 AM

Re: reduce voltage - by denver - 03-18-2010, 01:58 PM

Re: reduce voltage - by rghines1 - 03-18-2010, 06:37 PM

Re: reduce voltage - by denver - 03-18-2010, 07:37 PM

Re: reduce voltage - by denver - 03-21-2010, 07:04 PM

Re: reduce voltage - by denver - 04-06-2010, 04:22 PM

Re: reduce voltage - by Ron Ramirez - 04-06-2010, 05:05 PM

Re: reduce voltage - by rghines1 - 04-07-2010, 09:28 AM

Re: reduce voltage - by codefox1 - 04-07-2010, 11:27 AM

View a Printable Version

Users browsing this thread: 1 Guest(s)

Recent Posts
Philco 42-345 Restoration/Repair
Yes, 57 is an electrolytic cap that should be 12 mfd 400 volts according to the parts list from the Phorum library schem...RodB — 06:01 PM
Philco 42-345 Restoration/Repair
Looks like if I am reading it correctly it looks like the silver capacitor#57 that appears to be a replacement is of a l...osanders0311 — 05:09 PM
Philco model 38 code 121 not receiving signal.
Thanks Arran. Yeah this plastic is pretty thin. It's a little thinner than the original stuff. It kinda reminds me of p...Stormlord5500 — 04:37 PM
Testing a speaker and output transformer Trutone A2-G
The equivalent of one short turn is basically the same as that of a shorted load. If it is the primary's turn, then the ...morzh — 03:53 PM
Testing a speaker and output transformer Trutone A2-G
I've never had an output transformer become shorted, the failure mode is usually an open primary, or in a center tapped ...Arran — 03:52 PM
Philco model 38 code 121 not receiving signal.
As long as the plastic sheeting isn't too thick, I think that the thickness of photographic film would be just about rig...Arran — 03:19 PM
Philco model 38 code 121 not receiving signal.
Well why not! :lol:Stormlord5500 — 03:14 PM
Philco model 38 code 121 not receiving signal.
Good luck next thing you know you will be winding coils just for the fun of it. DavidDavid — 11:29 AM
Testing a speaker and output transformer Trutone A2-G
morzh Short-circuited turns can be considered as a half-dead transformer. But on this case transformer will hot and s...Vlad95 — 11:01 AM
Testing a speaker and output transformer Trutone A2-G
I am not sure how a transformer could be weak. It could be inadequate, but only when you replace the original with somet...morzh — 09:56 AM

Who's Online

There are currently 2220 online users. [Complete List]
» 2 Member(s) | 2218 Guest(s)

Login
Username:
Password:	Lost Password?
	Remember me