Railway42 said:
Hi Andy
The decoder +/ ground is not DC so I think that is what the buzzing is. You don't say what relay board or circuit you are using and also what voltage the decoder output is set to. Let me know and I will try to sort it out.
Railway42
Hi there,
So I'm using an ESU Loksound 4 XL, and trying to drive two miniature 12v DPDT relays, set up so that I'm reversing the DC polarity to the pantograph motors on the roof.
Since asking the question I've had some joy. If I leave the CV for the output at 31, so full track voltage, the relay operates correctly. Which is fine on the 12v supply of the programmer, but once on track voltage, the 22v will wreck them. The buzzing occured when I reduced the cv below 31 to try and get a lower voltage.
I then spotted a 10v output from the ESU 4XL, and connected the relay to AUX 7. This set up is now working. When I tried this 10v terminal to AUX 6 and below, when the output was off I was getting -4 volts, and +10 volts when it was on. AUX 7 is zero volts when off, and the relays seem happy to operate at 10v
What is the voltage on decoder+/ground? Is it some form of PWM?
Andy