Time relay

[miguelnoda]

Hello buy a relay time for my stage 300B and put it after the high tesion 30 seconds jumps and shakes the speaker cones.
Anyone know the exact placement for not doing this?
the device is this (Power Supply Board Action Delay 300B 2A3 KT88 tube amp) (Sophia Electric)
thanks

 

[dgta]

Post the schematic of the amp and power supply with the relay. Someone will be able to help you.

 

[Burnedfingers]

Your english needs work and its hard to understand you but I will take a guess. You bought a (Power Supply Board Action Delay 300B 2A3 KT88 tube amp) (Sophia Electric) and now the thing bangs on and your speakers shake?

 

[miguelnoda]

time delay

right, when entering the high voltage moves the cones of the speakers

 

[popilin]

Try the relay switch-on after warm up of tubes.
You need first power the filaments, say 30 seconds.
Use a cheap speaker to test, just in case.
Or even better, short circuit the output of the amp with another relay during start up.

 

[LinuksGuru]

Connect 4-5H choke in B+ in order to build CLC filter..

 

[miguelnoda]

time delay

you could make me a schema
thanks

 

[VaNarn]

It appears that you need to fit suppressor networks across the relay switch contacts.This is usually a 0.1mFd capacitor in series with a 100 Ohm resistor.The capacitor should be rated to suit the B+ voltage with a healthy safety margin if there are filter chokes in the supply rail.

 

[popilin]

you could make me a schema
thanks

Try this.
Relay contacts are conected to speakers output, short circuit in "power off", after time delay, relay is "power on" and short circuit is removed.
Need a three contacts relay.
Time delay is about 10sec. If so much, decrease R, say 470K
NEVER power up a valve amp without a load.

 

[miguelnoda]

time delay

I send the schematic to see where I put the time delay or diodes
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[VaNarn]

Since the voltage and current ratings for the relay contacts are unknown,the obvious place for the delay switching is between the H.T.winding centre-tap and the connection to ground.

 

[roline]

When I use damper diodes for delayed B+, I use the standard C-L-C filter for the supply hash and then add the diode and cap. This last cap becomes the Max B+ that I use to bias the output transformers. Then R-C for second stade and R-C for first stage like normal.
For the C-L-C filter be sure to use enough of a safety margine for the cap's voltage rating, stack them if you need to.
I've used this method on power amps and pre/headphone amps to prevent turn on noise, and turn on overvoltage.

 

[2wo]

If you replace the 5U4 with a indirectly heated rectifier, you won't need the delay circuit at all...John