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:

Recent Posts
Philco Model 38-7: what caps & resistors do fail typically?
Since you stated earlier, you have a console 38-7XX. They also had a 38-7T (table), and 38-7CS (chairside). A very nic...GarySP — 01:18 PM
Part numbers to model cross
That I wouldn't know, but sometimes the radio document itself shows one, same as the capacitor cans' etc pinouts.morzh — 12:46 PM
Part numbers to model cross
Thank you morzh, that is exactly what I was looking for. Now , is there some where that shows pinouts for Philco power ...Jim Dutridge — 11:37 AM
Restoration of the Canadian General Electric A-87
Thanks for your help Michael. In fact, this video is only an intermediate result. Later I had to apply another tinting l...RadioSvit — 09:01 AM
Restoration of the Canadian General Electric A-87
Great job on the cabinet. PS. In the US notation, "kenotron" refers to specific type of tubes; we call re...morzh — 08:24 AM
Part numbers to model cross
This document has at least some tables of models and parts used. Example: Choke 32-7572, used in 604 radio. Search f...morzh — 08:19 AM
Restoration of the Canadian General Electric A-87
I also checked all the radio tubes on my Hickok 530 tube tester. The 5Z3 kenotron turned out to be faulty, all the other...RadioSvit — 08:02 AM
Restoration of the Canadian General Electric A-87
Well... While the varnish is drying up, I started repairing the chassis... Of course I started by replacing the pa...RadioSvit — 07:12 AM
Philco Model 38-7: what caps & resistors do fail typically?
Hello Martin, Welcome aboard our little community what great Model 38-7 Sincerely Richardradiorich — 12:30 AM
Philco Model 38-7: what caps & resistors do fail typically?
Welcome to the Phorum Martin. I count about 9 paper caps, the 3 electrolytic caps and 2-Y2 safety caps to replace th...RodB — 09:44 PM

Who's Online

There are currently 1438 online users. [Complete List]
» 1 Member(s) | 1437 Guest(s)

Login
Username:
Password:	Lost Password?
	Remember me