how to make darkness circuit (4 circuits)

1. LDR Darkness circuit diagram using 555 

Components

capacitor

1000uf 25v -1

10uf 25v -1

0.01 uf -1

Resistor

1KΩ – 3

LDR – 1

Bridge Rectifier -1 or 1N 4007 diode – 4 pc for making Bridge rectifier

1N4007 diode – 1

IC 555 – 1

Transistor – 2N2222A- 1

Relay 6V – 1

Preset 1MΩ – 1

2. LDR Darkness circuit using the comparator 

√ Tested

Note- LDR must keep away from the light of the load bulb for flicker less operation. You can do this using the covering of the side area of LDR using black tape.

Demo testing Video Of LDR Darkness circuit using the comparator 

Components

Resistors

10K-1

220Ω-1

510Ω or 470Ω -1

56K-1 (Not compulsory)

Capacitors

 1000uf 25v-1

220nf (224)-1

C2 = 220uf or 100uf 25v-1

Variable resistor 22K-1

Diode

1N4007-4 

Transformer

0-6v 500ma- 1

IC

LM358 (comparator)-1

MOC3021 (optocoupler- 1

Transistor BC548-1

Triac BT138-1

LDR (12mm)-1

 

Download – Gerber_PCB_ldr

 

3 &4 . Photodiode darkness circuit diagram

This circuit diagram is made using the photodiode as the light sensor or dark sensor with the lm358 comparator. Highly sensitive and flicker less.

√ Tested

Video of photodiode dark sensor circuit

.

As my testing experience, Although Both LDR and Photodiode based circuit works well, But The LDR based circuit is better than photodiode based darkness circuit.

 

Note- Pinout of transistor BC547 and BC548 are same

 

Also Read

Single Touch ON OFF Switch Using 555 And 4017

12v Battery Charger circuit with Overcharge Protection

Stereo Audio Amplifier Circuit Using CD6283

How To Connect Microphone with Any Amplifier