Control sound and lights on analogue..

[PhilP]

Need some lateral thinking here..

Have a 2095 'whizzy-cranks' diesel, which has a Massoth 'S' decoder in it for sound.. The loco, and line it runs on, is analogue...
Am trying to control the lights, and sound, by using a physical switch (the original LGB '0-1-2' switch) on the loco.

Now the switch has two parts to it (bear with me on this!):
First section is a double-pole, OFF-ON 1-ON 2 switch - That is '0' all off. '1' first pair connects to second pair only. '2' first pair connects to third pair only.
Second section is a double-pole, OFF-OFF-ON switch - That is positions '0' and '1' are both OFF. Position '2' is ON.

Now to complicate things a little!
There is a Massoth DC Motor Controller fitted. - This block power to the motor, until about 6.5V is present.. This allows lights, and sound, to come up before the loco moves. - You can also sit with the sound idling and the lights on.

Because this is an analogue loco / line I have problems with using the LGB board (and switch) to control things.

What I am after is a way to control the (directional) lights with the decoder (easy, just connect them up) BUT also have a way to turn them off using the LGB switch. - Now, I can do this by using part of the switch to control the +ve. common on the lights. I will have to rewire the rear light board, but not a problem.
However, if the 'S' decoder is on, then the sound will also be on (analogue remember).
I could turn the sound off, by cutting the power to the decoder, but that also cuts off power to the lights..

I have tried several ways to do this using the LGB switch, and wiring it in different ways, but unless I just route the loudspeaker output through part of the switch I can not see a way to achieve this. - I am asking Massoth if it is permissible to run a decoder for any length of time without a speaker connected.


Anyone out there have any thoughts?
Thanks,
PhilP.

 

[stockers]

Yep - switch the speaker wire.

 

[Neil Robinson]

I am asking Massoth if it is permissible to run a decoder for any length of time without a speaker connected.
.

I strongly suspect it is. However you could always arrange a switch to swap the speaker for a suitable resistor of similar resistance and power.

 

[stockers]

What happens when you reduce a volume controller to zero?

 

[PhilP]

What happens when you reduce a volume controller to zero?

That is too easy! - Unless, of course, the Client opted NOT to have one fitted!

To be fair, I guess most people don't fiddle with the volume control, even when fitted, they tend to turn the sound off..
You can reach under, and flick the switch, a lot easier than trying to adjust a bottom-mounted volume control..

Thanks all, for your input.. I will not hold my breath, and see what Massoth say about running one of their decoders into an open circuit.

 

[stockers]

You miss my point Phil. The posts immediately above are discussing the possibility of switching out the speaker - the open circuit that you refer to

 

[PhilP]

You miss my point Phil. The posts immediately above are discussing the possibility of switching out the speaker - the open circuit that you refer to

That would not normally present an open circuit (or very high resistance/impedance to the output stage..
Either you control the gain (a control voltage, or alter a feedback value), or the volume control acts as a fader. If done properly, it should present a constant impedance to the circuit. - Though I doubt Massoth do this!
I would *think* it should be fine.. I guess they have made it pretty bullet-proof? Let's face it, ham-fisted b*gg*rs like me are fitting / fiddling with them!