Power supply rectifiers [message #8810] |
Fri, 04 February 2005 17:57 |
|
Wayne Parham
Messages: 18783 Registered: January 2001
|
Illuminati (33rd Degree) |
|
|
While building the Stoetkit, I noticed that it uses 1N400x rectifiers. All of the signal capacitors are nice, and the transformers are great. But the power supply uses electrolytics and plain ol' 1N400x diodes. So I think maybe I could probably improve some there, just with component substitutions.We've had discussions on this forum about fast recovery diodes, FREDs and HEXFREDs and also about Schottky diodes. I'm thinking one of my first upgrades will be to improve the rectifiers, but I'm wondering which to go with. I'll probably grab some datasheets and give this some thought, and I'd also like to hear your experiences.
|
|
|
|
|
|
Re: Try a Snubber Filter, too... [message #8815 is a reply to message #8810] |
Sun, 06 February 2005 10:50 |
TubeCraft
Messages: 30 Registered: May 2009
|
Baron |
|
|
The Bottleheads swear by them. I think all the parts can be had at the Rat Shack. It's just like a Pi filter but with an identical resistor in both lines. Use RS ceramic .01 1.5kv for the caps and cheap 10R 10W cement resistors (the more inductive the better). The resistors really help the inrush problem too. I built my regulated bench supply this way. Transformer>snubber>diodes>PS filter --|--VVVV--|--->|--- = = | --|--VVVV--|--->|-- Just a thought. Regards, TC
|
|
|
|
|
I gotcha [message #8818 is a reply to message #8817] |
Sun, 06 February 2005 16:38 |
PakProtector
Messages: 935 Registered: May 2009
|
Illuminati (2nd Degree) |
|
|
Hey-hey!!!, I got forced into using a common TX for both the B+ and a DC filament supply. It is Schottky rectified and L-C, but there is still a little bit of buzz which matches the switching of the diodes. It is just at edge of perception, but knowing why it is there is bugging me. Guess I'll put a dedicated TX under there and be done with it. this'll give me a few more options for other experiments. I am going to put .01 uF caps across each of the Schottky diodes and see if that helps first... regards, Douglas
|
|
|
Re: Power supply rectifiers [message #8832 is a reply to message #8810] |
Sat, 19 February 2005 20:45 |
Poindexter
Messages: 108 Registered: May 2009
|
Viscount |
|
|
Hey, Wayne, Sorry to enter the fray so late. My budget fave is Diodes, Inc. ultrafast switching rectifiers, their number UF1007, which have otherwise the exact same specs as 1N4007. Digi-Key sells these for 29¢, if you buy a hundred; a lifetime supply for a hobbyist. They are not 'soft' recovery, but their PN burst is very high-freek and short duration; thus very easily shuntable. I use a .01µF 716P on each side of the diode set (transformer and filter), and have gotten very good results; clear, fast, quiet. How many you need for your Stoetkit? I'll send them along. Poinz
|
|
|
|