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Use 2v Signal to Control 12v LED strip

I'm sorry if this title is confusing, but let me try to explain. If this is in the wrong section please let me know.

I am currently working on a DIY project where I currently have a board that runs on 3v that is a receiver for motorcycle signals. So whenever my blinkers activate, the device will turn on the 2v LEDs for that signal. Ex Left, Right, or Brakes.

I want to modify this and attach it to 10 LED strips that are 12v with 60ma per strip. The LEDs have their own separate power supply, but I am needing to control/complete the circuit with the 2v LED signal. I am willing to actually remove the LEDs on the board with transistor or MOSFET, but I am confused on what is the correct way to do this. Also if I am even going about it the correct way. Any help would be amazing.
 

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Mosfet would be good if you can find one with a low enough turn on...don't know for sure what the requirement is for the L series. I've often used them for logic circuits (5V)
Could make up a voltage doubler(or trippler) and drive the gate with that I suppose.
Other than that, a transistor should do ok if you are willing to live with a small amount of voltage drop.
If you need a circuit, Google along those lines.
 
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Mosfet would be good if you can find one with a low enough turn on...don't know for sure what the requirement is for the L series. I've often used them for logic circuits (5V)
Could make up a voltage doubler(or trippler) and drive the gate with that I suppose.
Other than that, a transistor should do ok if you are willing to live with a small amount of voltage drop.
If you need a circuit, Google along those lines.
I researched into the MOSFET, but am coming up short on knowing which one would work.
 

Harald Kapp

Moderator
Moderator
Nah, don't use an electromechanical relay. It will work for some time but will probably wear out rather quickly, especially when used on a motorbike with the accompanying shake, rattle and roll :)
An electronic solution using a transistor is way better. At only 2V of signal level, a MOSFEt that turns reliably on is not that easy to find. You may consider using a bipolar transistor which requires only ~0.7V (at the cost of some base current). We have a ressource on how to use this kind of transistor to switch a load here.
 
Nah, don't use an electromechanical relay. It will work for some time but will probably wear out rather quickly, especially when used on a motorbike with the accompanying shake, rattle and roll :)
An electronic solution using a transistor is way better. At only 2V of signal level, a MOSFEt that turns reliably on is not that easy to find. You may consider using a bipolar transistor which requires only ~0.7V (at the cost of some base current). We have a ressource on how to use this kind of transistor to switch a load here.
Thats what I was worried about for using a relay. Also that the relays would be slower than a transistor or MOSFET.

So I started looking into Bipolar Transistors and came across http://www.farnell.com/datasheets/1700327.pdf
Would that work for what I am trying to do with my current Voltage/Current going through it? Or am I looking in the wrong place?
 

Harald Kapp

Moderator
Moderator
This is a PNP transistor. You'll probably want to use an NPN transistor, depending on the polarity of your 2V drive signal. You'll also need a current limiting resistor in series with teh base, see the ressource I linked.
The relevant parameters of the transistor are:
Vceo >= 20V (as you are going to drive 12V LEDs and you'll want some headroom)
Ic >= 100mA (you want to drive 60mA, also some headroom is desirable)
For Ic=60mA and assuming a current gain of >=100, your base current is 60mA/100=600µA. The base-emitter voltage drop is approx. 0.7V. That leaves 2V-0.7V=1.3V across the base series resistor. 1.3V/600µA translates into Rbase=2.2kΩ.
 
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