Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: loudandproud on March 14, 2016, 03:33:37 pm

Title: Switching Relay and Relay Power supply issues
Post by: loudandproud on March 14, 2016, 03:33:37 pm
Hey Ampers!  New to the forum and need help.  I purchased a switching relay and relay power supply kit from Doug and assembled them last night.  The power supply (as you guys know) uses power from the warmers of, in my case, a 12ax7 and converts the voltage of two heaters to a 5 volt dc output with powers the relay.  In my amp (DrZ Zlux), pins 9 and 4 and 5 (4/5 are connected) are heaters and each register 3.3ish volts individually.  I did the test wiring and, although the power supply board produced a little under 5 volts dc output as expected, the bridge on the power supply board promptly got hot, and started smoking. I'm grounding this to the main ground. Obviously, I've screwed up somewhere or the bridge was bad to start with (doubtful).........so.......suggestions........issues......tests?  Thanks for the help.
Title: Re: Switching Relay and Relay Power supply issues
Post by: DummyLoad on March 14, 2016, 04:26:03 pm
if your 6.3v winding has a center tap and it is grounded and you grounded the (-) term of the bridge, then you just smoked some silicon. to use a bridge disconnect the center tap.

Title: Re: Switching Relay and Relay Power supply issues
Post by: tubenit on March 14, 2016, 05:15:31 pm
Lots of great information, picture, schematics, layouts  etc....... on relay switching in ARCHIVES

http://el34world.com/Forum/index.php?topic=14348.0 (http://el34world.com/Forum/index.php?topic=14348.0)

With respect, Tubenit
Title: Re: Switching Relay and Relay Power supply issues
Post by: loudandproud on March 15, 2016, 06:38:24 am
Thanks guys.  Extremely helpful.