Momentary footswitch with led

Started by Buffalo Tom, October 11, 2017, 01:49:48 AM

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Buffalo Tom

Hi. Im building a footswitch for the MUTE foot switch jack on a Radial JX-44. According to the manual it needs to be a momentary switch. I have wired up a "Carling SPST SW110-PM-Off" and it works great. So now I want a led that indicates when its muted. So I started to look for schematics that can turn on/off a led with a momentary switch and I found a 555 timer circuit that I built and it works great too. But here comes the problem! When I connect both the Radial JX-44 and the 555 timer circuit to the switch it starting to act strange. The radial JX-44 leds blink, the switch does not trig as it should and I need to press multiply times, and the led on the foot switch sometimes stays on even when I press the switch again. Can I use diodes to isolate the two circuits when they are connected to the same switch? Need help

My circuit to turn on/off the led


From Radial manual.


bluebunny

I would say you need a double-pole switch, otherwise you're connecting two disparate circuits together and they're (not unsurprisingly) not getting along.
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Ohm's Law - much like Coles Law, but with less cabbage...

Rob Strand

The other problem you might  find is the LED circuit and the unit get out of whack. 
There's nothing telling the LED circuit what state (on or off) the Radial JX-44 thinks it is in.
Sometimes these thing magically power-up in the same state then one day they don't, then you
realize it's kind of random.

Send:     . .- .-. - .... / - --- / --. --- .-. -
According to the water analogy of electricity, transistor leakage is caused by holes.

Redvers

Don't want to put you off but do you really need an LED to tell you when your signal is completely cut off?

If I had to do it I might look at tapping into the onboard status led, running it down a shared  trs cable to the footswitch. At least the logic is taken care of. Maybe that's crazier than the original idea. ..

Rob Strand

QuoteIf I had to do it I might look at tapping into the onboard status led, running it down a shared  trs cable to the footswitch.

Probably better but more wires.

What about give-up using the built in mute, build a mute box with you own LED, wire your signal through that?
Send:     . .- .-. - .... / - --- / --. --- .-. -
According to the water analogy of electricity, transistor leakage is caused by holes.

Buffalo Tom

Quote from: bluebunny on October 11, 2017, 02:27:30 AM
I would say you need a double-pole switch, otherwise you're connecting two disparate circuits together and they're (not unsurprisingly) not getting along.

Thanks will look into this

Buffalo Tom

Quote from: Rob Strand on October 11, 2017, 02:52:00 AM
The other problem you might  find is the LED circuit and the unit get out of whack. 
There's nothing telling the LED circuit what state (on or off) the Radial JX-44 thinks it is in.
Sometimes these thing magically power-up in the same state then one day they don't, then you
realize it's kind of random.

I was thinking this might be a problem.. But the Radial JX-44 always power up unmuted even if it was muted when the power was shut down. Same thing with the 555 timer circuit I use for the led. It does not remember its last position and always power up with led off.