Simple Dark Detect LED Robot's Flashlight
by syfrog in Circuits > Sensors
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Simple Dark Detect LED Robot's Flashlight
I'm going to show you a simple, adjustable light sensor circuit that activates in low light.
Light sensing circuits are versatile and simple enough for beginners to build but have many useful applications.
The circuit I am presenting is to be used as a headlamp for my robot A3-8D (anyone in manufacturing may get joke.) This lamp will automatically turn on when the robot enters a dark room. This will save precious microprocessor inputs and outputs.
Light sensing circuits are versatile and simple enough for beginners to build but have many useful applications.
The circuit I am presenting is to be used as a headlamp for my robot A3-8D (anyone in manufacturing may get joke.) This lamp will automatically turn on when the robot enters a dark room. This will save precious microprocessor inputs and outputs.
The Schematic and the Parts
The schematic is daily simple and there are not too many part required
Parts you will need:
- LEDs from a dollar store flashlight
- 1 x Transistor 2N4401
- 1 x Photoresistor
- 1 x 100 ohm resistor
- 1 x 100K ohm Variable-resistor
- Breadboard and hookup wire
- Perfboard, wire and soldering materials
Parts you will need:
- LEDs from a dollar store flashlight
- 1 x Transistor 2N4401
- 1 x Photoresistor
- 1 x 100 ohm resistor
- 1 x 100K ohm Variable-resistor
- Breadboard and hookup wire
- Perfboard, wire and soldering materials
Prototype Before Soldering
Even a simple circuit like this I take the time to layout on a board board and test before soldering. It's better to find you have a bad component or bad idea here than once it is on the CB. Desoldering is a pain.
I soldered some solid core leads on my led package to make it easier to breadboard.
I soldered some solid core leads on my led package to make it easier to breadboard.
Solder It Up and Cable It
I laid out my board so that the POT is facing out the direction of the lamp. When this is placed behind the skin of my robot I can have an access hole for adjusting the ON sensitivity without removing any panels.
Run 2 wires to the board for power and ground. I will be powering this with 5vdc.
Run 2 wires to the board for power and ground. I will be powering this with 5vdc.
Mounted and Tested
This the Lamp mounted in the robot skin of A3-8D. The lamp works great too bad the robot is not autonomous yet.
He is pretty bare bones so far with only a USB power charging port and Bluetooth speaker system and a few sound sensors. I will share this circuit as soon as I can get it wrote up.
Thanks
He is pretty bare bones so far with only a USB power charging port and Bluetooth speaker system and a few sound sensors. I will share this circuit as soon as I can get it wrote up.
Thanks