In this post we are talking about this handy little gadget called a 5V single-channel relay module. It is super useful for our microcontroller projects whether we are using Arduino, Raspberry Pi, or even the ESP8266/ESP32. Let us break it down together, what it is, how it works, and how we can connect it. Understanding […]
Relay
220V Solid State Relay (SSR) Circuit using Triac and OptoCoupler
An AC mains solid state relay or SSR is a device which is used for switching heavy AC loads at mains level, through isolated minimal DC voltage triggers, without incorporating mechanical moving contacts. In this post I have explained how to construct a simple mains operated solid state relay or an SSR circuit using a […]
10 Step Relay Selector Switch Circuit Diagram
In this post I have explained a simple yet useful 10 step selector switch circuit which can be operated using a singe push-to-ON switch. In the following design the circuit is used as a 3 step, single push motor speed controller unit. The circuit was requested by Mr.Edalcor. Technical Specifications hi sir good day to to you, can you please design […]
Grid Mains to Generator Changeover Relay Circuit
In this post I have explained a simple configuration which can be used as a automatic changeover circuit for switching AC grid mains to generator mains, during power failures or outages. The explained circuit will effectively switch the connected appliances to the generator mains during power failure however it won’t be able to switch start the generator automatically, […]
Prevent Relay Arcing using RC Snubber Circuits
In this article I have explained the formula and techniques of configuring RC circuit networks for controlling the arcing across relay contacts while switching heavy inductive loads. Arc suppression An arc is produced across the contacts when a switch or a relay is opened. With time, this condition can wear down the contacts. To overcome […]
Temperature Controlled Relay Switch Circuit
In this article I have explained a simple temperature controlled relay circuit which can be switched ON/OFF depending on the temperature on its temperature sensor. Meaning, when the temperature on its temperature sensor rises above a set threshold point, the relay switches ON, and when the temperature drops below the threshold, the relay switches OFF. […]





