|
Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders. |
|
|
|
Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders. |
|
In Reply to: Insanity! posted by Lynn Olson on September 16, 2002 at 02:16:16:
Lynn,Your point about miswired outlets is well taken. It's a good idea to check outlets all the time.
The type of B+ supply mentioned was used in low cost table radios with bakelite cases. A series heater string was used, allowing cheap transformerless construction. My father had such a radio that used a 117Z6 as the voltage doubler.
IF (very big if) the wall outlet has been wired properly, a RELATIVELY safe P/S can be built. Connect the safety ground wire to the metal chassis. Build the "classic" full wave doubler with a 117Z6 or a pair of damper diodes. Wire the "hot" lead to the center of the filter capacitor stack. Wire the "neutral" lead to the 2 discrete diodes, then wire the diodes to the ends of the filter capacitor stack. SS diodes are out, since they have high pulse current capability. Current, not voltage, kills; therefore, proper fusing of the "hot" line as it connects to the filter capacitor stack is ESSENTIAL. A DPDT switch that interupts both the "hot" and "neutral" leads should be used too.
Of course, isolation from the AC mains by transformer is THE WAY TO GO.
Eli D.
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Re: Insanity! - Eli Duttman 12:40:54 09/16/02 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2024, Audio Asylum, all rights reserved ]
