Optocoupler

An opto-isolator (also called an optocoupler, photocoupler, or optical isolator) is an electronic component that transfers electrical signals between two isolated circuits by using light. Opto-isolators prevent high voltages from affecting the system receiving the signal. Commercially available opto-isolators withstand input-to-output voltages up to 10 kV and voltage transients with speeds up to 25 kV/μs. A common type of opto-isolator consists of an LED and a phototransistor in the same opaque package. Other types of source-sensor combinations include LED-photodiode, LED-LASCR, and lamp-photoresistor pairs. Usually opto-isolators transfer digital (on-off) signals, but some techniques allow them to be used with analog signals.

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MQTT ESP8266 Home Automation Project 2021

“How to make MQTT ESP8266 NodeMCU Home Automation project to control relays from the switch and smartphone (Circuit + Code) through internet. In this IoT project, I have shown how to make an MQTT ESP8266 Home Automation project to control a …

Resettable E-Fuse

“A simple, cheap short circuit protector, controllable either manually or using a microcontroller. There are many E-fuses available both precises ones, used in industrial or critical situations, and [cheap] maker-friendly ones which despite doing their job, but are not suitable …

Bridging the gap between old and new, garage door gets a Wi-Fi controller

“This project started a long time ago, the idea is to be able to control the two garage doors remotly. Before anything else, you have to understand how the door is working, each door has one button, press it, it …

How to Make an AC Softstarter

“In this project I will show you why my new autotransformer keeps tripping my circuit breaker and how I built an AC softstarter in order to “softly” start the transformer so that it does not trip my circuit breaker. Along …

USB MIDI Adapter

“Simple USB to MIDI adapter based on an Arduino Micro or Leonardo, optionally with the ability to filter the MIDI data. I searched the net how to build a USB to MIDI adapter using an Arduino, but unfortunately I only …

Creating a MIDI Pass-Through Recorder

“Create an inline MIDI recording with an Arduino, an SD card module, and never lose your musical noodling ever again! Creating a MIDI pass-through recorder If you’ve ever used audio software on the computer, you probably know that MIDI …

Make your UPS smarter with ESP8266 and PCF8591

“The UPS did not shut down the computer in the event of a power outage. This hack makes the UPS smarter, I made this circuit with ESP8266 I have a well-functioning UPS with a faulty network interface, I use it …

$20 Synth Project

“This guide is for complete beginners in electronics & synth making. We’ll be building the ‘Helios One’, a total bastard of a synth a MIDI controlled synth made from a low cost Arduino micro-controller and the Mozzi audio library. Even …

Arduino MIDI Poly Synth - MiniSy (Musical Instrument)

“3 Oscillators Polyphonic Synth with MIDI using the Arduino Nano. My simple project of a Polyphonic Synthetizer using the Arduino Nano. It is simple but it is possible to play music with it. Up to 3 musical notes can be …

Raspberry Pi Shutdown Indicator

“It’s very simple circuit for showing operational status of raspberry pi (Hereinafter as RPI). Maybe it’s useful when you running RPI as headless (without monitor). Sometimes I’m concerned when is right time for completely power-off after shutdown …