need help with bypass LED on EA trem

Started by jlullo, April 23, 2007, 01:20:44 PM

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jlullo

alright... so i got a little ahead of myself before.  i built markm's version of the EA trem, and am trying to use the led also as the bypass LED.

I was playing around with it yesterday, and had it like this:


that worked great, but when i plugged it in, there was no trem.  only the bypassed signal, even though the LED indicator would switch on and off.

could someone please help me figure this out?

jonathan

jlullo


jlullo

i've been playing around with this quite a bit.  basically, as close as i can get it is where i solder a wire coming from the middle lug on the 3pdt switch to the trace connecting the - led to Q3.  when this happens, the light stops pulsing when bypassed, but doesn't turn off.

runoffgroove has this:
""marrstians" reports that the pulsing LED can also serve as a status indicator when using a 3PDT bypass switch. Simply use the third pole of the switch to break the connection between the LED and the collector of Q3 when bypassed."

i tried the same thing with a pole in the third row, but no results with that...

any ideas?

jlullo

if i can't figure this out, i might just put in a regular diode and wire up a status LED.... would pretty much any diode work out for this?

dachshund

One pole of the 3PDT switch is used to make or break the connection to the LED.
This means inserting the switch into one of the wires going to the LED.

Remove that wire you have going to the switch now (it's not connected in a way that will make this work).

If you cut one of the wires to the LED, you've opened the circuit at that point.
If you touch the two wires again, the circuit is closed, and the LED should blink and the tremolo should "tremolo". Yes?

You need to use one pole of the switch to make or break this connection in the same way.

(I don't have any way to draw this or post pictures here, at the moment.)

jlullo

like this?


this is what i'm doing, and when bypassed, the LED stays on, but does not pulse... if i move it to one of the lugs below it, the light will turn on and off, but not pulse

dachshund

Almost! Both wires are attached to the same lug of the switch. Move one to the lug directly below, which is the middle lug.


jlullo

 i've tried that, and the led will turn on and off when it is supposed to, but not pulse.. why is that?

dachshund

Hmm... I can't tell from the picture the orientation of the switch. Do you have the input & output signals connected to the switch? Can we see how that's drawn?

jlullo

#9
this is how i have it wired up...

would wiring it a different way lend itself better to this situation?

jlullo

sorry for the enormous pictures by the way

dxm1

You might try this:

1) Remove the jumper from the lower left and lower center lugs.
2) Move the ground wire to the lower left lug.
3) Grab the red wire from the board, and remove it from the LED.
   Put the free end on the middle center lug.
4) Add a wire from the middle top lug to the LED.

jlullo

dxm... should i do all of those changes, or just try them one at a time?

dxm1

You'll need to do them all at once to get it to work. You're rewiring the switch...

jlullo

#14
i don't know why i even asked that :) haha

my brain is getting fried...


so, i'm taking the positive lead and wiring it to the switch, and then from the switch to the LED.  am i leaving the - side wired to the board, right?

dxm1

Yes. You could do the same thing with the other lead as well - all you're doing is adding a switch in the LED circuit.

jlullo

dxm... no dice.. now, the LED isn't turning on at all

jlullo

nevermind, i made a stupid mistake, and had my polarities reversed...

works PERFECT

thank you so much for your help guys!  i appreciate your time!