Main > Main Forum

LED powering question

Pages: << < (4/6) > >>

mvolke1:


--- Quote from: RandyT on October 20, 2014, 11:38:30 am ---
--- Quote from: PL1 on October 20, 2014, 12:45:24 am ---:banghead:  Didn't think about this earlier, but you could just wire the two CDRs in series to drop 4.5v on each.

--- End quote ---

This probably won't provide the effect desired, unless the wiring is chained without removing the inline resistors.  These are what make them 5v. 

Running LED's at 12v is really inefficient, when there are not multiples in series, as the resistor needs to work much harder.  You can see this when using one of the online calculators.  The same LED which requires a 1/2 watt resistor at 5v, will require a 2 watt resistor at 12v.  In other words, expect it to get a lot warmer, as the differential between it's specified voltage and the supply voltage increases.

Something else to be aware of when running LED's in series is that the best case when one malfunctions, is that all of the units in series will stop working until the bad one is replaced.  Worst case is that you no longer have that voltage drop you were relying on, resulting in the destruction of the others in the series circuit.

--- End quote ---

Randy,

Do you have a lamp I could switch out with the lamp it came with that would work with my other 12v buttons?

RandyT:


--- Quote from: mvolke1 on October 20, 2014, 12:13:34 pm ---Do you have a lamp I could switch out with the lamp it came with that would work with my other 12v buttons?

--- End quote ---

No.  You could use one of the low output LEDs, such as those which are used with the buttons, but the light will be MUCH dimmer.  As PL1 suggested earlier, the way to do this would be to add an additional resistor in-line.  A 1 watt 82-ohm would probably do the trick, but monitor the resistor temp to make sure nothing is getting too warm.

If you have a 5vDC power terminal on your USB interface, you could probably get away with two of the CDR units running from it.  But you should check with the manufacturer to see how much current it can deliver.

mvolke1:


--- Quote from: RandyT on October 20, 2014, 01:10:04 pm ---
--- Quote from: mvolke1 on October 20, 2014, 12:13:34 pm ---Do you have a lamp I could switch out with the lamp it came with that would work with my other 12v buttons?

--- End quote ---

No.  You could use one of the low output LEDs, such as those which are used with the buttons, but the light will be MUCH dimmer.  As PL1 suggested earlier, the way to do this would be to add an additional resistor in-line.  A 1 watt 82-ohm would probably do the trick, but monitor the resistor temp to make sure nothing is getting too warm.

If you have a 5vDC power terminal on your USB interface, you could probably get away with two of the CDR units running from it.  But you should check with the manufacturer to see how much current it can deliver.

--- End quote ---

Hey Randy,

Thanks for getting back to me.

Do you think I could take the lamp from one of these: http://www.arcadeemulator.net/cgi-bin/shop/cp-app.cgi?usr=51F1020295&rnd=7660633&rrc=N&affl=&cip=&act=&aff=&pg=prod&ref=Rectangular+Pushbutton&cat=Low+Profile+Illuminated&catstr=HOME:Pushbuttons:Low+Profile+Illuminated

They look quite similar.

If I did do the resister, where would I add it?

RandyT:


--- Quote from: mvolke1 on October 20, 2014, 01:33:36 pm ---Do you think I could take the lamp from one of these...

--- End quote ---

If you would like a standard bulb instead of the LED, I can substitute one for you.  I'm sure I have a bag full here. :)


--- Quote ---If I did do the resister, where would I add it?

--- End quote ---

It would go between the power supply and one of the wires (in series).  Either wire is ok to do this with.

mvolke1:


--- Quote from: RandyT on October 20, 2014, 01:59:05 pm ---
--- Quote from: mvolke1 on October 20, 2014, 01:33:36 pm ---Do you think I could take the lamp from one of these...

--- End quote ---

If you would like a standard bulb instead of the LED, I can substitute one for you.  I'm sure I have a bag full here. :)


--- Quote ---If I did do the resister, where would I add it?

--- End quote ---

It would go between the power supply and one of the wires (in series).  Either wire is ok to do this with.

--- End quote ---

Hey Randy,

I would be more than happy if you have a standard bulb. I just want to make this as easy as possible.

If the standard bulb is just a matter of popping one out and the other in, and it'll work with my adapter safely, I'll be more than happy to do that. How can we make that happen?

Pages: << < (4/6) > >>

Go to full version