SSR or Solid state relays are high power electrical switches that work without involving mechanical contacts, instead they use just a couple of solid state semiconductors like MOSFETs for switching an electrical load, smoothly, and with high efficiency. SSRs can be used for operating high power loads, through a small input trigger voltage with negligible […]
Relay
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 […]
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 […]
Control a Relay ON OFF Using SIM Card, Mobile Phone, and Arduino
This project I will explain how we can control a relay remotely using a SIM card and a normal mobile phone, with help of Arduino and a GSM module. The relay can be turned ON or OFF by sending an SMS or by making a phone call to the SIM card placed inside the GSM […]
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, […]
How to Connect a Relay through an Opto-Coupler
In the following post I have explained how to drive a relay by using an isolated method, or through an optocoupler device. We will learn three methods, first method is by connecting relay directly with the optocoupler output pins, second method is by using external PNP transistors, and third method is by using external NPN […]