More than 1 LED

[AdamB]

Hey,

Besides draining power from a battery quicker, is there any side effect to using multiple LED's to show the on/off status of a pedal?

Also, how would I wire these up, in parallel or in series?

Cheers,
-Adam

[The Tone God]

Besides draining the battery quicker you are also using up what current the battery can supply at that moment. Too much pull could cause other parts of the circuit to miss-operate.

Parallel or series ? Depends on the situation. You have not given enough information to make a fair assessment but if forced to make a choice I would go with parallel. In either case you will have to adjust your current limiting resistor since the load situation has changed.

Andrew

[stm]

With a clever arrangement you can have two and even three LED's in a box with the same power consumption FROM THE BATTERY as one LED.

First, you need a constant current source. A JFET like a J201, 2N5458 or similar will make a good current source if you hardwire the Gate to the Source.  The trick is that you need to find a JFET with an Idss in the range of 2 to 5 mA (depending on how much current you want to feed to your LEDs).

Place all the LEDs in series with the current source between Vbat and GND, and use the corresponding switch/footswitch to SHORT the LEDs you want to turn off in the chain.  In this way, your power consumption is kept constant at Idss*Vbat, regardless on how many LEDs are ON.

With the method described above you will always have said power consumption whether there is a lit LED or not. One advantage of this is that any clicking produced by an LED changing state should be minimized since current drawn from the supply remains untouched.

Eventually you can have one of the switches OPEN the LED chain when the effect is in bypass to save that power.