madbeanpedals::forum

General => Open Discussion => Topic started by: peAk on March 21, 2014, 02:09:12 AM

Title: Bi-color LED question
Post by: peAk on March 21, 2014, 02:09:12 AM
On my Sharkfin, there is a dedicated LED for the LFO rate. Is possible to wire this so that a bi-color LED switches between colors rather than on/off?

Probably a silly question......
Title: Re: Bi-color LED question
Post by: mattlee0037 on March 21, 2014, 02:12:07 AM
http://gaussmarkov.net/images/1590B_SETUP_GNDIN.bmp
If it is common anode wire one cathode normally to the switch (top middle green wire) and wire the other cathode to the bottom middle lug and remove that green jumper. Your circuit won't be grounded in bypass, but it's not a high gain circuit so it shouldn't make a difference. 
Title: Re: Bi-color LED question
Post by: haveyouseenhim on March 21, 2014, 02:16:58 AM
It would probably take a two transistor rig. Maybe have the + side of where the led is connected to the bases of the transistors to turn power on and off to the two positives of the LED.

This is based off my very limited knowledge. ;D
Title: Re: Bi-color LED question
Post by: Stomptown on March 21, 2014, 04:22:50 AM
Probably a silly question......
[/quote]
Quote from: mattlee0037 on March 21, 2014, 02:12:07 AM
http://gaussmarkov.net/images/1590B_SETUP_GNDIN.bmp
If it is common anode wire one cathode normally to the switch (top middle green wire) and wire the other cathode to the bottom middle lug and remove that green jumper. Your circuit won't be grounded in bypass, but it's not a high gain circuit so it shouldn't make a difference. 

The rate led looks like it is connected to the sample/hold switch so I'm not sure the diagram you posted really works for this scenario. Maybe I'm wrong but it seems like you would have to supply power to the 2nd anode and connect that to the bottom left lug of the sample/hold switch.

(power->4.7K resistor -> 2nd anode -> bottom left lug on sample/hold switch)

The only problem with this method is the led would only flash in sample/hold mode. It is possible I am wrong here so hopefully someone can chime in to shed some light.
Title: Re: Bi-color LED question
Post by: mattlee0037 on March 21, 2014, 05:12:28 AM
Ahhh did not read it for was for LFO rate. That would only work for general on/off bypass switching.
Title: Re: Bi-color LED question
Post by: m-Kresol on March 21, 2014, 07:30:39 AM
how about that:

your common cathode gets soldered to the PCBs pad. Instead of wiring the anode (+) pad directly to the led, solder a wire to the centre lug of one of the rows of the 3pdt switch. Top lug of the row connects to one of the LEDs anodes, the bottom lug to the other.
This way you should always ground the LED in either position (on/bypass), so your LFO is indicated also in bypass. When you engage the effect, the colour should switch. I hope that makes sense.
Title: Re: Bi-color LED question
Post by: peAk on March 21, 2014, 01:00:32 PM
Some good suggestions and I will attemp them and see what works.

I don't mind if the LED turns completely off when I am not in sample and hold. I may actually prefer that.

Title: Re: Bi-color LED question
Post by: m-Kresol on March 21, 2014, 01:05:18 PM
Quote from: peAk on March 21, 2014, 01:00:32 PM
Some good suggestions and I will attemp them and see what works.

I don't mind if the LED turns completely off when I am not in sample and hold. I may actually prefer that.

In that case, a bicoloured LED is not even necessary. Just take a regular LED and wire the cathode to the 3PDT switch instead of the bypass indicator LED. That way, the LED should just be active when the effect is engaged.
Title: Re: Bi-color LED question
Post by: peAk on March 21, 2014, 01:11:39 PM
Quote from: m-Kresol on March 21, 2014, 01:05:18 PM
Quote from: peAk on March 21, 2014, 01:00:32 PM
Some good suggestions and I will attemp them and see what works.

I don't mind if the LED turns completely off when I am not in sample and hold. I may actually prefer that.

In that case, a bicoloured LED is not even necessary. Just take a regular LED and wire the cathode to the 3PDT switch instead of the bypass indicator LED. That way, the LED should just be active when the effect is engaged.

sorry, I didn't mean that. I want an on/off bypass LED like normal but would like my 2nd LED (LFO Rate) to turn on and flash between colors when in sample and hold. It can turn completely off when not in sample and hold.