First I have to say that my knowledge about electronics is based only on a high school class a couple of years ago and the pages I read here about diodes and transistors.
I'm trying to make a computer controlled TV-remote, using an Arduino processor. After connecting the IR LED I realized I didn't have enough power, so I tried to connect it to an AA battery and control the led with a transistor.
My circuit looks as attached.
The initial problem was that the LED is constantly on, shining a little brighter when the Arduino leg is HIGH. Then I connected the transistor base through its resistor to ground (outside the Arduino), creating a power-free base-emitter circuit.
Oddly, the LED is still on. When I completely disconnect the base-emitter circuit, the LED turns off. To the best of my understanding, there shouldn't be current through the base in either of the cases, so the transistor should not permit current through the LED circuit.
Am I using the transistor wrong? Overloading it? Did I just create a source of unlimited free energy?
Thanks for any help.
I'm trying to make a computer controlled TV-remote, using an Arduino processor. After connecting the IR LED I realized I didn't have enough power, so I tried to connect it to an AA battery and control the led with a transistor.
My circuit looks as attached.
The initial problem was that the LED is constantly on, shining a little brighter when the Arduino leg is HIGH. Then I connected the transistor base through its resistor to ground (outside the Arduino), creating a power-free base-emitter circuit.
Oddly, the LED is still on. When I completely disconnect the base-emitter circuit, the LED turns off. To the best of my understanding, there shouldn't be current through the base in either of the cases, so the transistor should not permit current through the LED circuit.
Am I using the transistor wrong? Overloading it? Did I just create a source of unlimited free energy?
Thanks for any help.
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