LED Help

[crew]

I am having lots of issues with my DIY LED light

I have the following
2 ELN 60-48P Drivers (PWM signal)
an arduino controller which Im fairly certain is wired correctly as the display works fine
an LCD shield
a RTC clock

here is my issue.. I can't get my LED's to fire. I have only hooked up one because I didn't want to hook up everything and then have it not work so I am working with the RB led's for the moment, 10 of them.

My multimeter is showing 0.038A so there is some current running through, but the pot inside the driver doesnt seem to do anything to increase it. I haven't broken it, I was very careful to not twist it too far. Is there anyone here that can help me out?

 

[darcurr]

sounds like no PWM signal. Do you have any means to check it?

 

[crew]

I have no idea how to check it..

 

[roundman]

How did you wire it up? Did you put a pot for manual dimming?

 

[crew]

I'm an idiot, just realized that I didn't have a full circuit.. I had the positive connected to the RB and the negative connected to the CW.

I fixed that issue and the lights came on, dim tho. I turned the pot inside the driver up a little bit and the lights got very bright. now my issue is controlling them with the arduino.. they are only dimming manually via the pot inside the driver. Another issue im having is getting an amp reading. When I touch the LED's with my multimeter, the lights instantly turn off and im getting a reading higher than is possible for the driver or the LED's (1.5A.) When I remove the prongs from the multimeter, the lights come back on.

Edit: how im wired up

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[crew]

Another question.. I know I need a 1k resistor.. but how many watts, does it matter? and with the 10 volt power adapter, how many amps?? Im using a 1 amp, figured that was right

Edit: the 10v power supply im using, im not really sure which side is positive so I switched the wires to see if maybe that would fix the issue. the leds still turn on, but very dim and turning the pot doesn't make them brighter.. both wires are white (one with a dashed black line) I have read that the marked wire is positive, but if thats the case the LED's were brighter when they were wired incorrectly.. wired both ways, the light doesn't respond to the arduino

 

[darcurr]

Crew;662360 wrote: I'm an idiot, just realized that I didn't have a full circuit.. I had the positive connected to the RB and the negative connected to the CW.

I fixed that issue and the lights came on, dim tho. I turned the pot inside the driver up a little bit and the lights got very bright. now my issue is controlling them with the arduino.. they are only dimming manually via the pot inside the driver. Another issue im having is getting an amp reading. When I touch the LED's with my multimeter, the lights instantly turn off and im getting a reading higher than is possible for the driver or the LED's (1.5A.) When I remove the prongs from the multimeter, the lights come back on.

Edit: how im wired up

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Happens to the best of us. The issue with your meter sounds like you are putting it in parallel rather than in series. In other words, it should just be part of the led string. A meter is a dead short in current sensing mode, hence if you put it across the led string as you would to read voltage, you just shorted the whole thing. That would also give you a ridiculously high current reading.

 

[darcurr]

Crew;662374 wrote: Another question.. I know I need a 1k resistor.. but how many watts, does it matter? and with the 10 volt power adapter, how many amps?? Im using a 1 amp, figured that was right

Edit: the 10v power supply im using, im not really sure which side is positive so I switched the wires to see if maybe that would fix the issue. the leds still turn on, but very dim and turning the pot doesn't make them brighter.. both wires are white (one with a dashed black line) I have read that the marked wire is positive, but if thats the case the LED's were brighter when they were wired incorrectly.. wired both ways, the light doesn't respond to the arduino

The 10v input should be high impedance, your 1 amp supply is more than enough. Also the 1k resistor shouldn't have to be enormous, 3.5 - 5 watt should be sufficient. I think most wall warts have dash marks on the positive led. I have thought about using an Arduino, but haven't yet. The concept though is to use the transistor as a switch. So your diagram is correct. I would use my meter on the PWM circuit at say 50% duty. that translates to 5v on most multi-meters since they average. then change the PWM output to 25% and 75% which should read 2.5v and 7.5v respectively. If not, I would suspect an Arduino issue.

 

[crew]

I've been using a 1/4 watt 1k resistor.. Too low?

Edit: Thanks again for the help, I do recommend the arduino, I'm just trying to figure it out myself. I can send you my finished sketch (code) if you want to use it in the future

 

[pwest]

Crew;662434 wrote: I've been using a 1/4 watt 1k resistor.. Too low?

That resistor is on the base of the transistor, so the power requirement (when in ON state) will be approximately P = V^2/R, where V ~ 4.3, so P ~ 18.5/1000 or 18 mW--your 1/4 W resistor is more than enough.

Take a look at the instructions and video at http://reefledlights.com/how-to-adjust-your-eln-60-48-driver/">http://reefledlights.com/how-to-adjust-your-eln-60-48-driver/</a> . This shows you how to adjust the driver with the analog voltage input (not the PWM version that you have). But, if you connect your 10v supply directly to the driver input (bypass the transistor) you can adjust your drivers for full on as shown in the video. Disconnect the 10V supply and your LEDs should go off. If that happens, then you know everything is working OK (and properly adjusted). Then, you can go back to checking out the Arduino output and the transistor circuit.

-Phil

 

[crew]

Wow, just typed a really long message and my "token" expired so now I have to retype it... here we go..

Edit: I tried hooking the power supply up directly to the driver like was suggested above and here are the results..

Set up #1 I mentioned earlier that I am not entirely sure about the positive and negative wires on my 10v Power Supply (one wire is white, the other is white with black dashes) In this set up I have hooked up the dashed wire as positive because that seems to be what most people agree is positive. I turned the pot inside the driver to 0 and plugged it in. The LED's came on at what I would assume is about 70-80% brightness and then adjusted up to 100% (assumed) with less than a quarter of a turn of the pot. When I unplugged just the power supply, the LED's dimmed down to what I would assume is between 5-10% brightness and then stayed there for 20 seconds before I pulled the main plug. The LED's then got really bright and clicked off (I think this is the LED's discharging everything remaining in the capacitor?)

Set up #2
I decided to switch the wires because it seems like the LED's shouldn't turn on with the pot turned all the way down, 0A should equal 0 light correct? I plugged everything in and then turned on the power strip. Nothing happened which seems like the correct response I would think. I turned the pot and the lights started to come on, but as I turned, the LED's did not get very bright. With the pot all the way up, the LED's seemed to be about 5-10% brightness. When I unplugged the power supply, nothing happened. When I unplugged the main power, the lights slowly got brighter and then discharged like before...

I have no idea what is going on. I have lots of beer. If anyone wants to come help me out, I would really appreciate it.

Edit: Forgot to mention a few things..

I have the power supply and the main power plugged in to a surge protector/power strip thing. I can't imagine this would be my problem, but I thought I would mention it just in case.

In set up #1 my multimeter read 0A at all the way down and .070 at all the way up (seems wrong, maybe I don't know how to use my multimeter, very possible)

In set up #2 my multimeter read .38A and didn't move.

I have my multimeter set to mA/A

 

[crew]

I figured it out, thanks for everyones help