B+ time delay relay - Page 3

nigelwright7557 · 10th April 2010, 11:40 PM

I use a PIC micro in my amp.
It currently holds off the output to teh speakers for 3 seconds.
It also monitors b+ and B- for a DC condition and switches off output to speaker if it spots a fault condition.

No reason why I couldnt add another relay to hold off B+ for a few seconds.

jeepy · 14th April 2010, 06:02 PM

[QUOTE=cbutterworth;1049672]OK, after getting my PSU (more-or-less) designed, I want to add a time-delay relay so that a single switch can be used to turn on the 6.3VAC heater transformer before the B+ transformer gets switched-on.

An article in Sound Practices shows how to do the job with 2 switches only!
On top of that you can heat your tubes for the time depending on your mood!

jeepy · 14th April 2010, 06:15 PM

[QUOTE=Alain Dupont;1058667]cbutterworth,

This works well. Also why not use the 'inactive position' of the relay to connect the power line to ground thru a 5-10k resistor so when you swith off the main you discharge quickly the psu capacitors who keep high voltage
longer than the heaters get cool.

tubekit · 31st August 2011, 11:30 AM

What about just using one of these, or something like it?

115C20T - Relay, time delay. 20-sec 115V SPST-NC-3A 9-pin - Relay_ time delay_ 20-sec 115V SPST-NC-3A 9-pin - 115C20T/

$20. Put it in the plate primary and use a separate filament tranny.

ratbagp · 31st August 2011, 12:53 PM

Another old solution that uses a separate filament transformer and two DPDT switches that are rated at normal 120 or 240 line voltages. I get mine from Radio Shack.

Dual DPDT Switch

It's simple and works well except if there is an outage followed quickly by the restoration of power. It's actually not that much of a disadvantage since the tubes are still warm.

ray

10th April 2010, 11:40 PM	#21
nigelwright7557 diyAudio Member Join Date: Apr 2008 Location: Carlisle, England	I use a PIC micro in my amp. It currently holds off the output to teh speakers for 3 seconds. It also monitors b+ and B- for a DC condition and switches off output to speaker if it spots a fault condition. No reason why I couldnt add another relay to hold off B+ for a few seconds. __________________ http://www.murtonpikesystems.co.uk PCBCAD40 pcb design software.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Relay delay	Ted205	Chip Amps	16	24th September 2008 05:44 PM
on/off thump - use Time Delay Relay ?	redrabbit	Everything Else	0	29th June 2008 02:01 AM
Delay-Off relay	peace brainerd	Parts	7	12th May 2007 03:14 AM
cheap time delay relay for soft start?	mpmarino	Parts	0	20th January 2007 09:47 PM
Time Delay Relay Tubes	cadman	Tubes / Valves	8	17th December 2002 04:25 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read

14th April 2010, 06:02 PM	#22
jeepy diyAudio Member Join Date: Feb 2010	[QUOTE=cbutterworth;1049672]OK, after getting my PSU (more-or-less) designed, I want to add a time-delay relay so that a single switch can be used to turn on the 6.3VAC heater transformer before the B+ transformer gets switched-on. An article in Sound Practices shows how to do the job with 2 switches only! On top of that you can heat your tubes for the time depending on your mood!

14th April 2010, 06:15 PM	#23
jeepy diyAudio Member Join Date: Feb 2010	[QUOTE=Alain Dupont;1058667]cbutterworth, This works well. Also why not use the 'inactive position' of the relay to connect the power line to ground thru a 5-10k resistor so when you swith off the main you discharge quickly the psu capacitors who keep high voltage longer than the heaters get cool.

31st August 2011, 11:30 AM	#24
tubekit diyAudio Member Join Date: Jun 2011	What about just using one of these, or something like it? 115C20T - Relay, time delay. 20-sec 115V SPST-NC-3A 9-pin - Relay_ time delay_ 20-sec 115V SPST-NC-3A 9-pin - 115C20T/ $20. Put it in the plate primary and use a separate filament tranny.

31st August 2011, 12:53 PM	#25
ratbagp diyAudio Member Join Date: Mar 2008 Location: North East, MD	Another old solution that uses a separate filament transformer and two DPDT switches that are rated at normal 120 or 240 line voltages. I get mine from Radio Shack. Dual DPDT Switch It's simple and works well except if there is an outage followed quickly by the restoration of power. It's actually not that much of a disadvantage since the tubes are still warm. ray

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)