They do like to cram those ls1's in there don't they!
Yes i should be able to fabricate some metal parts if needs be.
Ive a breadboard to test circuits on just need to get the correct components.
Hi Stu,
If you want to keep your LED Pedal design simple, how about using a couple of LM3914 LED Bargraph Drivers?? The voltage from a variable resistor swing from 0-5V , lights up 10 LED's exactly how you want..
any chance you could lay that out on a breadboard, think i do have a LM3914 in my kit of bits, I'm a novice when it comes to reading the diagrams though
ideally im looking to light up 14 leds per side.
Hi Stu,
If you want to keep your LED Pedal design simple, how about using a couple of LM3914 LED Bargraph Drivers?? The voltage from a variable resistor swing from 0-5V , lights up 10 LED's exactly how you want..
Thanks Mike
I was beginning to think it was a bad idea!
Stu,
Have a look at this link, it might help. Unfortunately it only runs 10 LEDs, although you can cascade them to make 20
If pin 9 is not connected (default), it will be in Dot-Mode. Connect pin 9 to pin 3 (+ on power supply) for Bargraph http://www.cpemma.co.uk/bargraph.html
Okay, as promised, here is a circuit I drew up. I may have made a few errors as nobody is perfect I am sure if I did, it will be pointed out. Anyways, I attached the schematics and sorry, it took two pages to fit everything. The jumper block is to set between Dot mode and Bar mode. The nets with labels simply means tie those point together. Hope that helps...
Ack, I already spotted one error. Pin 9 of U2 should be U2mode. My printer is out so it is hard to catch everything from the monitor
I will correct the error later as well as check it over one more time...
Here is data sheet link for 3914 **broken link removed**
Cheers guys, will get a lm3914 to play with, i've set the circuit up on the breadboard so we'll see if i get some pretty lights up and down with the pot lol!
Just to keep things ship shape and all that sort of thing I corrected an error, added a note for the jumper block, and updated the schematic. So here is the latest for your use
Oh, and here is a somewhat of a parts list. You need to pick your LEDS. Low current ones I would suggest.
------------------------------------------------------------------------
Qty. Value Ref Des.
1 .01uF C5
2 .1uF C2 C4
1 1.1k R2
2 10k R4
1 10k Pot R5
2 2.2uF C1 C3
1 2.4k R3
1 20k R1
20 D1 D2 D3 D4 D5 D6 D7 D8 D9 D10 D11 D12
D13 D14 D15 D16 D17 D18 D19 D20
1 Molex J1
2 LM3914 U1 U2
Once your happy with the setup of the basic LM3914 circuit
you will be delighted to discover that the chips can be cascaded to produce the desired result that you were looking for originally
Its purely for show and accuracy purposes, what I wish for the leds to do is something similar to this video when its put into the second stage via his mode change button https://www.youtube.com/watch?v=rs9oUvNfaBU
Thanks for all the input guys really appreciate the help.
See the +5v inputs, is that the max voltage a lm3914 will take, as it would have to run off 12v from the car.
I'm such a newb at reading the circuit diagrams
Thanks for all the input guys really appreciate the help.
See the +5v inputs, is that the max voltage a lm3914 will take, as it would have to run off 12v from the car.
I'm such a newb at reading the circuit diagrams
Ugh, your correct in your thinking. You want twelve volts, but the circuit I gave was for 5V (Will work at twelve but components values may need to be changed). I kinda assumed you might use a 5v voltage regulator like **broken link removed**
The Auto voltage is rather a noisy world and straight 12-14vdc from the auto might cause noise issues in the circuit (Such as sporadic led operation). A regulator would help clean up the standard auto volts.