What Determines Voltage Changes in LDR Darkness Sensors?

In summary, a darkness sensor circuit is an electronic circuit that detects the presence of darkness or light in its surroundings using a sensor, amplifier, and comparator. It can be used for various purposes such as controlling lights and triggering alarms. The main components needed to build one include a sensor, amplifier, comparator, resistors, capacitors, and a power supply. One limitation is that it cannot distinguish between natural and artificial light sources, but this can be overcome with a more sophisticated sensor or by adjusting the threshold value.
  • #1
Eisen
14
0
Here's the circuit-

darkness sensor.JPG


It isn't clear to me which part of this circuit makes the voltage divider and also it doesn't show where the voltage output is on the circuit. Can someone tell me those two things please. Also I don't understand why voltage increases as resistance increases in the LDR and why voltage decreases as resistance decreases in the LDR. Can someone explain that too please. It doesn't give an explanation why on this webpage I'm looking at.
 
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  • #2
Anyone?
 

Related to What Determines Voltage Changes in LDR Darkness Sensors?

1. What is a darkness sensor circuit?

A darkness sensor circuit is an electronic circuit that is designed to detect the presence of darkness or light in its surroundings. It uses a sensor, such as a photodiode or a phototransistor, to measure the amount of light and then triggers an output signal based on a set threshold.

2. How does a darkness sensor circuit work?

A darkness sensor circuit works by using a sensor to detect the amount of light in its surroundings. The sensor is connected to an amplifier, which amplifies the signal and sends it to a comparator. The comparator compares the signal to a set threshold and triggers an output when the signal falls below the threshold, indicating darkness.

3. What can a darkness sensor circuit be used for?

A darkness sensor circuit can be used for a variety of purposes, such as controlling streetlights, turning on and off indoor lights, and triggering alarms when it gets dark. It can also be used in projects like automatic plant watering systems or automatic blinds.

4. What components are needed to build a darkness sensor circuit?

The main components needed to build a darkness sensor circuit include a sensor, such as a photodiode or a phototransistor, an amplifier, a comparator, resistors, capacitors, and a power supply. Additionally, a microcontroller or a timer IC can be used to control the output signal.

5. Are there any limitations to using a darkness sensor circuit?

One limitation of using a darkness sensor circuit is that it cannot distinguish between natural and artificial light sources. For example, if a room is dimly lit with artificial light, the circuit may still trigger the output signal. This can be overcome by using a more sophisticated sensor or by adjusting the threshold value.

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