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Hoffman Amps Forum image Author Topic: channel switch with relays and LEDs  (Read 6475 times)

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Offline tubesornothing

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channel switch with relays and LEDs
« on: June 14, 2009, 06:35:02 pm »
Hey all, I am building another amp that has footswitch channel plus footswitch boost.  This time I am going to try using relays.  I am keen on have LEDs for the front panel as well as the footswitch.  I found a Marshall two button footswitch that work well for this.

The problem I am having is: how can I have two different LED lights for the channels (like red for dirty and green for clean) for the front panel?  I dont care about the footswitch, just the front panel.

Here is my schematic, thanks.

ToN


Offline Heinz

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Re: channel switch with relays and LEDs
« Reply #1 on: June 15, 2009, 03:22:51 pm »
Two simple solutions come to my mind:
  • you use a relay that has more switches than needed for your circuit and use one of these to switch the LEDs
  • you use a transistor for switching the LED that indicates footswitch 'off'. The other LED works the 'traditional' way.
in tranquilitate vis

Offline G._Hoffman

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Re: channel switch with relays and LEDs
« Reply #2 on: June 15, 2009, 03:45:39 pm »
There was a simpler way to do it in the Kevin O'Connor's first TUT book, though for the life of my I can't remember it at the moment. 


Gabriel

Offline tubesornothing

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Re: channel switch with relays and LEDs
« Reply #3 on: June 15, 2009, 03:56:39 pm »
Heinz thanks for the info.  I like the second idea, as it keeps "not so clean" power out of the switch mechanism.

Offline PRR

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Re: channel switch with relays and LEDs
« Reply #4 on: June 16, 2009, 06:59:12 pm »
If relay current is much greater than LED current, just do this:

 


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