In this post I have explained an upgraded version of my previous mains 220V/120V high-low voltage cut off protection circuit which now includes a delayed restoration of power for the load with 3 LED power status indicators. The idea was requested by one of the dedicated members of this website. Circuit Objectives and Requirements Main […]
Mains
Solid-State Inverter/Mains AC Changeover Circuits Using Triacs
In this post I have explained 2 simple concepts for making solid-state triac based Inverter/mains AC changeover circuit, the idea was requested by Music girl. Technical Specifications I would like to replace the SPDT relay with 2 scr’s. Would you consider a circuit to replace those changeover relays? I believe a relay would need to […]
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, […]
Arduino Mains Failure Battery Backup Circuit
In this article I have explained a simple mains failure backup circuit for providing Arduino boards an uninterruptible supply during such situations. The idea was requested by Mr. Fredrik. Technical Specifications This blog gave me a lot of interesting information. Especially the power supply circuit with battery backup part. The reason for this is that […]
LCD 220V Mains Timer Circuit – Plug and Play Timer
In this post we are going to make an LCD 220 V mains operated timer using Arduino whose countdown time can be witnessed via 16 x 2 LCD display. Introduction The proposed LCD timer circuit is general purpose timer with display and few buttons for setting the time. Once the time is set output goes […]
Password Controlled AC Mains ON/OFF Switch
In this post I will show how to construct a password based mains ON/OFF switch circuit, which can turn ON and OFF the AC mains supply, only when correct password is entered. This prevents the danger of electrocution of the technician who might be currently working with the high voltage lines and equipment. Password Protection […]





