Relay or switch mains - Page 2 - diyAudio
Go Back   Home > Forums > Design & Build > Parts

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 16th July 2012, 12:34 PM   #11
diyAudio Member
 
Join Date: Jun 2011
Location: Hobart Australia
Thanks for all the feedback there is still a lot to consider. It seems that maybe noise is not going to be a issue if I lay out properly. If I do run ac to the front panel it will pass one of the large smoothing caps most likely quite closely. Perhaps shielding is an option.
Cheers
  Reply With Quote
Old 16th July 2012, 04:12 PM   #12
diyAudio Member
 
indianajo's Avatar
 
Join Date: Jan 2010
Location: Jeffersonville, Indiana USA
Peavey triggers the triac with mains AC limited by a resistor and diode through a low cost switch. You only get the hard edge from a triac when it turns on, a triac turn off at ~ two volts AC. So the Power up silence circuit (a J174 jfet with an RC delay) cuts any noise at turn on until the DC power supplies are at full voltage. A relay or hard contact switch can also produce a large sharp voltage edge at turn off.
The triac is in the AC part of the amp, away from the preamp boards. There is a steel divider in the case like a PAS2 preamp between AC and sound.
__________________
Dynakit ST70, ST120, PAS2,Hammond H182(2 ea),H112,A100,10-82TC,Peavey CS800S,1.3K, SP2-XT's, T-300 HF Proj's, Steinway console, Herald RA88a mixer, Wurlitzer 4500, 4300

Last edited by indianajo; 16th July 2012 at 04:22 PM.
  Reply With Quote
Old 17th July 2012, 06:37 AM   #13
diyAudio Member
 
Join Date: Jul 2003
Location: Dona paula, Goa
...and diode through a low cost switch...

I suspect it me be a diac.

Gajanan Phadte
  Reply With Quote
Old 17th July 2012, 01:42 PM   #14
marce is offline marce  United Kingdom
diyAudio Member
 
Join Date: Jun 2007
Location: Blackburn, Lancs
A simple relay would do, why use a noisy traic!
  Reply With Quote
Old 17th July 2012, 02:29 PM   #15
Mooly is online now Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Even Nelson Pass used a triac in the A752 PSU.
Attached Images
File Type: jpg A75 PSU.JPG (43.7 KB, 95 views)
__________________
-------------------------------------------------------
Installing and using LTspice. From beginner to advanced.
  Reply With Quote
Old 17th July 2012, 03:07 PM   #16
oshifis is offline oshifis  Hungary
diyAudio Member
 
Join Date: Mar 2004
Location: Budapest, Hungary
Using a SSR (Solid-State Relay) is an elegant solution, but it needs an external control current for the internal LED. I turn on my power amplifier from my preamplifier this way.
  Reply With Quote
Old 17th July 2012, 03:57 PM   #17
diyAudio Member
 
jacco vermeulen's Avatar
 
Join Date: Oct 2004
Location: At the sea front, Rotterdam or Curaçao
Send a message via Yahoo to jacco vermeulen
Quote:
Originally Posted by Mooly View Post
Even Nelson Pass used a triac in the A75 PSU.
Please add that Papa included a snubber across the triac, plus C1/C3, to help suppress/shorten the transients.
Could have been Mr Thagard's wrong doing (couple of years later he did the A100 with stacked BJT/MOSFET output stages for Audio magazine single-handed, with a few pointers from Mr P)
Back in the late '80s and early '90s everyone was into triacs, me included, remote switching monaurals on/off with the preamp signal and a timer was comfortable.
Not very Audio-Pile nowadays, other more elegant ways.
__________________
The buck stops Here
  Reply With Quote
Old 17th July 2012, 04:34 PM   #18
marce is offline marce  United Kingdom
diyAudio Member
 
Join Date: Jun 2007
Location: Blackburn, Lancs
Still noisy compaed to other soilutions, I cannot remember when I last did a board with a triac, possibly 15 years ago, look at dimmer switches, yes they are a bit better these days than the RF transmitters they use to be, but why add anything that could add noise, when everywhere else we try to reduce it.
  Reply With Quote
Old 17th July 2012, 04:54 PM   #19
diyAudio Member
 
indianajo's Avatar
 
Join Date: Jan 2010
Location: Jeffersonville, Indiana USA
Quote:
Originally Posted by Mooly View Post
Even Nelson Pass used a triac in the A752 PSU.
Thanks for the circuit. Peavey doesn't have this pcb on the schematic on eserviceinfo.com and since this is working okay I really didn't want to pull the board out and trace it out to understand it. See, no diode on the trigger- learned something.
__________________
Dynakit ST70, ST120, PAS2,Hammond H182(2 ea),H112,A100,10-82TC,Peavey CS800S,1.3K, SP2-XT's, T-300 HF Proj's, Steinway console, Herald RA88a mixer, Wurlitzer 4500, 4300
  Reply With Quote
Old 17th July 2012, 05:53 PM   #20
diyAudio Member
 
Join Date: Nov 2008
Location: Victoria,TX
Blog Entries: 1
Hi,
What about using the MOC3061. This will power up the amplifier clean since it is start at zero crossing of the AC. Attached it is the technical data. Also you can use a zero crossing relay Omron G3NE-220T-US. I found it no too long ago I am planning to using it in my new design.
Attached Files
File Type: pdf MOC3061.pdf (143.1 KB, 17 views)
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Mains relay help please :D 6L6 Power Supplies 9 31st May 2012 05:02 PM
Mains Relay blowing Fuse on GC k3ys3r_soz3 Chip Amps 2 6th March 2007 06:25 PM
cap across mains switch? klitgt Power Supplies 4 11th December 2006 09:27 PM
Never try to switch 450V DC at 3A with a conventional mains switch... Eva Power Supplies 28 1st November 2006 10:24 AM
Mains Switch Problems Angel-Baby Solid State 4 23rd March 2004 07:42 PM


New To Site? Need Help?

All times are GMT. The time now is 06:00 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2