Wiring several leds

[jimilee]

Thank you very much! I think i'm going to use less leds,
maybe 7 or 6, because i think that if i use 9, the pedal will be eating to much mA of the power supply.
But anyway, thanks to all the help guys, and thanks for the explanation RobA.

Best regards

Naaa, just do what I do and make it happen. If it doesn't work, scale it back. The vero board is the way t go though. Makes it easer and cleaner. I don't quite understand all the maths, so as a basss player I just put stuff together, and if somethin splodes, well that's cool too, and lesson learned. Just enjoy it and don't over think it. 

[RobA]

Thank you very much! I think i'm going to use less leds,
maybe 7 or 6, because i think that if i use 9, the pedal will be eating to much mA of the power supply.
But anyway, thanks to all the help guys, and thanks for the explanation RobA.

Best regards

You could try upping the values of the CLR's and see if the total brightness is still OK. With some of the super bright LED's, you can use a pretty low current and get good brightness out of it. I used some slide pots with LED's on a preamp I made for my Godin and I wanted the current to be really low because there were a couple of them and it runs on a battery. So, I tried them with 47kΩ CLRs and they are plenty bright at that level.

If you want nine LED's for the design, I think you can get LED's and CLR's that'll make it work and be within a reasonable current budget. Nine blue LED's at 1mA current might just be too bright to look at anyway, so trying one with about a 47kΩ CLR would be a good place to start.

[RobA]

I had to try this out on the breadboard to see what it looked like . The thing I'm currently playing with has a 14V supply and my Tayda blue LED's measured a Vf of 2.7V, so I needed to up the value of the resistors to get something similar. I used a 68k for the single and 47k for the double diodes. That put me at 0.166mA and 0.183mA respectively. I had the LED's in a tight row and they looked plenty bright to me in full light. The total current draw would be 4 * 0.183mA + 0.166mA = 0.898mA. So the total for the nine diodes is less than 1mA. That's not bad at all. You might need to go up a bit on the current depending on your LED or the brightness you want, but I'm guessing that you can come in at less than 2mA total and that wouldn't be anything if you are running off an external power supply.

[RobA]

Since I had it sitting on the breadboard anyway, I figured a photo might help show the brightness level. I'm not the best photographer around, but I hope this helps a bit.



This is using the 68k and 47k resistors with the 14V supply. The diodes to the left haven't got anything to do with the LED circuit. They're part of the circuit I'm playing with. I figured I'd leave them in the picture to get an idea of the light level in the room.

[HailToTheBlues]

Thank you so much RobA, that helps a lot! And you're right, 2 mA isn't going to hurt my 1Spot.