Manual Part 2

Project 28 | INFRARED-CONTROLLED LIGHT

Project 29 | IR CONTROL

The phototransistor detects

light, including infrared light that

is invisible to the human eye.

The phototransistor detects light, including infrared light that

is invisible to the human eye. The white LED blinks even if you

press the remote control continuously, because the signal that

is coming from your remote control is a stream of infrared light

bursts. Each burst of infrared light causes a burst of current to

ow through the LED, making it blink.

You need an infrared remote control for this project, such as any TV/

stereo/DVD remote control in your home.

Build the circuit and turn on the switch (S1). Place the Q4 attachment on

the phototransistor (Q4). Position the circuit away from lights in the room

so that the white LED (D6) is off. Point your remote control directly into the

Q4 attachment, and press any button to turn on the white LED. The LED

may not get very bright.

You need an infrared remote control for this project, such as any TV/

stereo/DVD remote control in your home.

Turn on the slide switch (S1) and place the Q4 attachment on the

phototransistor (Q4). Position the circuit away from lights in the room so

that the white LED (D6) is off. Point your remote control directly into the Q4

attachment, and press any button to turn on the white LED.

Note that when the phototransistor (Q4) is activated by room lights the

white LED is on continuously, and when the phototransistor is activated by

your infrared remote control LED will be blinking.