Tag: Dark sensor
A breadboard is a device for testing temporary electronics projects. Components used to test a circuit can be reused for other projects. None of the components are damaged. Almost all people start to learn electronics using breadboard because it is the simplest way of making circuit. The photograph shows a typical small breadboard which is suitable for beginners building simple circuits with one or two ICs (chips).
The circuit is ready for testing. Connect battery terminals and see the output. As you block light falling on LDR(Light dependent resistor), the LED glows. OUTPUT: [youtube]http://www.youtube.com/watch?v=qmWAgoHwy3w[/youtube] THIS CIRCUIT IS EXTREMELY SENSITIVE TO DARKNESS. EXPERIMENT THE CIRCUIT IN A HIGHLY ILLUMINATED ROOM. LED GLOWS EVEN IN LESS DARKNESS. Use torch light if the LED glows in less darkness. You can adjust the sensitivity of the circuit using a variable resistor in place of R3-300Ohm. Try this circuit with other resistances as well, for example, 1K, 10K and 100K, etc.
Automatic Light detector using variable resistor A light detector senses light. As the light level increases and LDR meets the lowest threshold resistance, the circuit automatically turns on the LED D1. We can adjust the sensitivity using the preset VR1-10K. LESS RESISTANCE(VR1)-> LESS DARKNESS TO SWITCH OFF THE LED HIGH RESISTANCE(VR1)-> MORE DARKNESS TO SWITCH OFF THE LED
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