In our previous post, we designed a Refrigerator Door Open Alarm Circuit with IC 555 but however, in this post, we design a Simple LDR Based Refrigerator Door Warning Circuit without using any IC. Moreover, this circuit helps to alert the user when the fridge door stays open for a long time, as this simple […]
LDR Circuits
Mini Light Intensity Meter Circuit using LDR
Here, is very simple and useful mini light intensity meter circuit using LDR which uses one LM334 IC, one LDR, small analog milliamp meter and 1.5V battery or power supply. The circuit checks light level by changing meter current as per LDR resistance. When light increases, LDR resistance changes so meter needle moves, because of […]
LDR Based Morning Alarm Circuit using NAND Gate IC
A LDR Based Morning Alarm Circuit using NAND Gate IC helps switch on an alarm sound automatically when morning sunlight falls on the sensor. This circuit uses an LDR (Light Dependent Resistor) and a CD4011 NAND gate IC to detect light and as soon as sunlight reaches the LDR, the resistance of the LDR changes. […]
IC 741 Based Audible Light Sensor Circuit using LDR
The IC 741 Based Audible Light Sensor Circuit using LDR is a simple and useful electronic circuit which detects the change in light intensity and gives an audible sound through the speaker. Also, this circuit works like a light controlled pulse oscillator generator, as IC 741 gives pulse signals at the output and the speaker […]
Automatic Tone Generator Circuit using LDR and 555 IC
Want to build a smart sound circuit controlled by light? then this simple yet interesting electronics project is a perfect choice, which uses an LDR and 555 timer IC to generate different tone or beep sounds whenever the light level changes, making it best for alarms, warning systems and beginner electronics projects. The 555 timer […]
Simple LDR Based Light Detector Circuit using Timer 555 IC
Nowadays, light detector circuits are very useful in many small electronic projects, For example, we use them in automatic lamps, security alarms, and light sensing devices. In this Simple LDR Based Light Detector Circuit using Timer 555 IC, the IC works as the main control unit, along with that, the CDS photocell, also called LDR […]