Multiple LED's, Series or Parallel?

Hi All,

I finally got the old DerringerII alarm out of the car!  I hooked-up the Crimestopper alarm.  So far it seems to be working pretty good.

Anyhow, I got a LED question.  What is the recommended way to hook up LEDs?  In series or in parrallel?  A couple of things to consider.

-original alarm LED voltage output was 2volts

-original alarm had 3 LEDs-new Crimestopper voltage output is now 3volts-i'd like to hook up all 3 LEDS to the new alarm

Advice? comments?  tips?

Thanks!

PS:  are LED's "directional" in current?  As in, can I screw it up by hooking up neg terminal to the pos terminal on the LED?  Or will it simply not "work" unless I hook up the terminals correctly?

Yes there is the longer shaft of the diode is the postive or the most and standard is the side lead on flatside of bulb is negative."Big" Mike

Double Take

Fremont, Ne

remember to check all your wires with a dmm not a test light!!

i take no responsibilty whatsoever for the vailidty of the info nor consequences thereof

Something to consider, if you wire the LED's in series. If any of the LED's should fail. All of them will not function. If you wire the LED's in parallel, if one or more fail. The others will continue to work. Some alarms, require that the LED's be active, so if the LED's should not function anymore. Either the alarm will not perform normally, or it may function erracticly. You may hook up all three of the LED's directly without any resitors if you wish. If the leads to the LED are no longer different in length. Simply look into the LED, the thinner side of the LED is the positive (anode) and the larger pin is the negative (cathode) If you have a DMM with a diode check, you can varify that fact, as well the LED will light up to confirm the proper polarity. Regards EVIL Teken . . .

Evil Teken,

I talked to tech-support over at Crimestopper.  They said that I should wire the LEDs in series.  Apparenlty if I run it in parrallel, it would fry the LED output on the alarm brain.  The guy said 2 LEDs max in parallel.

So now I'm thinking.  Can't I wire 2 LEDs in parallel?  And then wire the whole circuit as a series? (or wire 2 LEDS in series with 1 LED parallel to that circuit?)

Am I talking out of my arse here?!

why not get a tri color led and wire that in"Big" Mike

Double Take

Fremont, Ne

remember to check all your wires with a dmm not a test light!!

i take no responsibilty whatsoever for the vailidty of the info nor consequences thereof

or use a transistor to handle all the current you want. then you can hook a million up...

Yes, you can do what you suggest.