Looking for Cheap 5V LED Drivers

[CrufflerSteve]

I've been playing around with an Arduino processor and one of things is making it turn LED's on. It has outputs of 5V 40 milliamps. Since they were cheap I bought bags of 5mm LED's from ebay. I'm thinking of making a few display amps to put under rocks & such so I'm looking for something to drive them safely. I'd probably have 5 to 20 LED's per display.

Steve

 

[Lynx_Arc]

I've been playing around with an Arduino processor and one of things is making it turn LED's on. It has outputs of 5V 40 milliamps. Since they were cheap I bought bags of 5mm LED's from ebay. I'm thinking of making a few display amps to put under rocks & such so I'm looking for something to drive them safely. I'd probably have 5 to 20 LED's per display.

Steve

40ma? somehow I don't think it is worth a driver at that low level of current you are probably better suited to get a linear regulator or resistor it.

 

[CrufflerSteve]

The 40 milliamp was per output. I really think it is closer to 20 milliamp when your're driving a bunch. A basic Arduino has 14 I/O's, 5V, and serial and is loaded via USB. Its a really cool little processor and easy to program. Great deal for $30. With the right resistor each I/O could easily run 2 5mm LEDs.

I was talking about something cheap to run 20 or more 5mm LED's. I collect rocks and was thinking about building displays with lights in the bottom. I did that for a selenite with 25 cold white LED's and it looks cool. I did have one linear regulator from an old project and with some resistors it should last years. I do have boxes of unregulated power supplies I'd like to use without blowing the lights.

Steve

 

[Lynx_Arc]

The 40 milliamp was per output. I really think it is closer to 20 milliamp when your're driving a bunch. A basic Arduino has 14 I/O's, 5V, and serial and is loaded via USB. Its a really cool little processor and easy to program. Great deal for $30. With the right resistor each I/O could easily run 2 5mm LEDs.

I was talking about something cheap to run 20 or more 5mm LED's. I collect rocks and was thinking about building displays with lights in the bottom. I did that for a selenite with 25 cold white LED's and it looks cool. I did have one linear regulator from an old project and with some resistors it should last years. I do have boxes of unregulated power supplies I'd like to use without blowing the lights.

Steve

You could try using a 500ma wallwart coupled with a linear regulator. Probably a 6v one would work ok and give you the headroom needed for the regulator to function easily. 20x20ma=400ma so you would need at least that much but if you are using generic LEDs you may consider driving them less than 20ma if using them a lot for longevity reasons.

 

[MikeAusC]

If you're just going to switch lights on'off you're most probably best off connecting in parallel multiple strings of three LEDs and a resistor in series and run them off 12 volts.

Then switch the 12 volts using a relay or a MOSFET from 5 volts.

Driving lots of white LEDs from 5 volts won't be cheap or more efficient than the solution above.