Circuit Breaker

Introduction

Many time we need to turn ON the circuit manually(or by a sensor) and turn OFF it automatically. In this tutorial, we will see how to turn ON microcontroller based circuit and then how to turn OFF it by the microcontroller itself.
                 This type of circuit is useful for battery operated circuit where circuit turns ON by your decision and turn OFF by the controller's decision i.e controller turn OFF itself by sensing any condition to save the power.
       Caution: following ckt is for Arduino and NodeMCU but if you want to use it for ESP8266 then you need to connect 3.3V regulator for ESP8266 supply. Remaining ckt remains the same.

Components Required:
      1) Momentary switch
      2) IR transmitter
      3) IR receiver
      4) Resistor R1=3.3k
      5) Resistor R2=10k
      6) IR transmitter
      7) IR receiver
      8) Capacitor 100nF
      9)  MOSFET bs170
     10) Voltage regulator 780
     11)  Capacitor 1000nF

Ckt1: Circuit Diagram

 

IR Transmitter Receiver Pair

                             In above ckt, IR transmitter-receiver pair is shown.  Ambient light should not be incident on IR receiver so I wrapped Transmitter and receiver heading towards each other  using black tap.

image1: IR transmitter-receiver pair

HOW IT WORKS?

1)Turning ON

                      S1 is pressed

                        |

                       Q1 turns ON

                       |

                      the controller turns ON 

                       |

                     The controller will turn the digital output pin D3 high

                       |

                  IR Tx turns ON

                       |

                   IR Rx starts conducting

                        |

                Gate of Q1 pulled up by IR Rx

         

                 Now, to turn OFF the controller, pin D3 (Digital Pin)is pulled LOW by the controller

2)  Turning OFF

                     when controller senses any condition where the controller needs to be turned OFF to save the power the 

the controller will pull Pin D3 to LOW

|

IR Tx turned OFF

|

IR Rx non-conducting

|

Q1gate pulled down to ground

|

Q1 turned OFF

|

Controller Turn OFF

                                                               

Program (Arduino/NodeMCU)                            

                               Following program will blink BuiltIn LED for 5 times and then turn OFF the controller by pulling D3 pin LOW

	//Author: Vivekanand Dhakane
	//Uploaded on: 2 March 2020
	#include <ESP8266WiFi.h>
	#define ctr 0 //D3 of NodeMCU
	int count=0;
	void setup() {
	WiFi.disconnect();
	WiFi.forceSleepBegin();
	// initialize digital pin LED_BUILTIN as an output.
	pinMode(LED_BUILTIN, OUTPUT);
	pinMode(ctr, OUTPUT);
	digitalWrite(ctr, HIGH);
	}
	// the loop function runs over and over again forever
	void loop() {
	digitalWrite(LED_BUILTIN, HIGH); // turn the LED on (HIGH is the voltage level)
	delay(1000); // wait for a second
	digitalWrite(LED_BUILTIN, LOW); // turn the LED off by making the voltage LOW
	delay(1000); // wait for a second
	count++;
	if(count==5)
	{
	WiFi.forceSleepWake();
	digitalWrite(ctr, LOW);
	}
	}

view raw CircuitBreaker.ino hosted with ❤ by GitHub

           


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 If you have any doubt , Please Write it in comment :-)