To improve their comfort and simplify their daily routine, people constantly come up with new devices. Today we will look at a device for remote control of a payload using claps. A homemade cotton switch is useful, for example, for turning on the light in the vestibule or pantry, where usually finding the right switch is a lot of inconvenience. For site readers https://samelectrik.ru we will tell you in detail how to make such a device with your own hands, what parts you need to prepare for this and how to assemble it.
Content:
- Assembly diagrams
- Video instructions
Assembly diagrams
All cotton or acoustic machines are united by the presence of a microphone in the circuit, which is needed to register sound. Also, the design provides an amplifier, trigger or time relay, to control the power switch.
In this circuit, operating from a 220V network, the signal from the electret microphone is fed to the transistor VT1 for amplification, then to the resistance matching node and the emitter follower on the transistor VT2. And then to the comparator and trigger, assembled on the K561TM2 digital microcircuit.
A comparator is necessary to protect the switch from acoustic interference, it cuts out too short or prolonged sounds. The signal that passed through the filter changes the state of the trigger (on or off), and that, in turn, controls the load through the power transistor, relay and thyristor. Any lamp, for example, an incandescent lamp, can act as it.
Here is a similarly intended assembly diagram of a homemade cotton switch - on an integrated timer.
For the convenience of studying the circuit, we have highlighted the main nodes on it: a microphone amplifier on a transistor KT3102, a comparator on a ne555 microcircuit, a TM561 trigger and a KT3102 transistor, which controls the power relay.
No less interesting will be the self-assembly of an acoustic relay on an Arduino microcontroller and ready-made modules for it, which will greatly simplify the understanding of the principles of work for beginners and will allow you to fine-tune some parameters work.
To make a cotton machine with your own hands, you need to prepare three boards:
- Arduino Nano;
- sound module;
- power relay module (note that it is 5 volts).
You also need a computer to download the firmware, a USB cable, and a 5 Volt power supply (any phone charger will do). You need to install the Arduino IDE program on your PC to flash the microcontroller. You can download it for free from the official website of the board developer.
By copying the text of the sketch (program) and pasting it into the Arduino IDE window, you can immediately flash the controller. By changing some parameters and rewriting the device, you can fine-tune a homemade sound relay for yourself for stable operation. As you can see from the diagram, four wires are connected to the controller: two for power. The yellow wire connected to pin 13 is for driving the power relay. Green is the control wire from the microphone module connected to the analog input A0 of the controller.
The microcircuit contains 8 analog inputs and 14 digital I / O pins. For our project, we took A0 and D13, since along with it the LED on the Arduino board lights up, and you can clearly see when a signal is sent to the relay module.
Arduino sketch for making a sound relay:Sketch
By changing the value of x in the line if (analogRead (Al)> x), we set the sensitivity threshold, the maximum value of which is 1024. By making changes to the delay line, the delay interval after the execution of the sketch is changed. This sets the readiness time for switching. In addition, the protective threshold against interference and false alarms is regulated. In addition, the microphone sensitivity can be adjusted with the variable resistor on the board using a small screwdriver.
To check and configure the circuit, we took the Arduino UNO board, based on the ATmega238 microcontroller. At the same time, any other models are suitable, since we do not use many pins of the board, and the sketch does not require high performance.
The video below clearly shows a homemade cotton switch that we assembled according to the provided diagram:
Video instructions
A few simple ideas for making your own acoustic light switch are provided in the video:
Now you know how to make a DIY cotton switch. We hope that the provided assembly options, simple diagrams and video tutorials were useful and interesting for you!
Also read:
- DIY time relay assembly
- How to make a pass-through light switch
- Remote lighting control systems