LED to power a DC motor

[kitcha]

Hi,

I am designing a circuit. It consists of two parts, the output of the
first part is an LED signal, which is ON/OFF based on certain
conditions. I require a DC motor to be powered on when the LED is in
ON state. Could you please suggest a suitable circuit for the same?

Thanks,
Regards,
Krishnamurthy.S

 

[Lostgallifreyan]

kitcha <kitcha315@gmail.com> wrote in news:469eff8e-542a-4326-ba99-
0e9df6e5f122@v5g2000prm.googlegroups.com:

Hi,

I am designing a circuit. It consists of two parts, the output of the
first part is an LED signal, which is ON/OFF based on certain
conditions. I require a DC motor to be powered on when the LED is in
ON state. Could you please suggest a suitable circuit for the same?

Thanks,
Regards,
Krishnamurthy.S

An NPN transistor. The motor goes on the colectr side, between it and the
load, the emitter to ground. The LED-s voltage goes via a resistor to the
base. So long as both circuits share the same ground, this should work.

http://www.eecs.tufts.edu/~dsculley/tutorial/transistors/transistors1.html

Another alternative is an N-channel MOSFET, like the IRF630. That will switch
a strong DC current, and it's cheap, but it's likely you'll need more than
the LED's forward voltage voltage on the gate, so tap the LED signal voltage
before the resistor in series with that LED, so you get at least 5V on that
gate, then it should work. (Though I suspect you might need 6V, or a MOSFET
that will work with lower gate voltage).