An efficient solid state single pole double throw or SPDT switch can be built using triacs for replacing a mechanical SPDT. In this post I have explained a simple solid state triac SPDT relay circuit, using an optocoupler and a couple of triacs, which can be used as an effective replacement for mechanical relays. The […]
New Circuit Projects
2 Simple Arduino Temperature Meter Circuits Explored
In this article, I will show how to construct a couple of easy Arduino temperature meter circuits which can be also used as a LED room thermometer circuit. The circuit is designed to display the readings in doted/bar LEDs. This project can be implemented for applications where ambient temperature plays a crucial role or it […]
Switching Two Alternate Loads ON/OFF with IC 555
In this post I have explained how to make a simple IC 555 based alternate relay timer circuit for toggling a couple of loads alternately with a specified length of delay, as determined by the calculated values of the relevant components. The idea was requested by Mr. Sanjoy. Circuit Objectives and Requirements The Design Referring […]
3 Phase Induction Motor Speed Controller Circuit
In this post I have explained the making of a simple 3 phase induction motor speed controller circuit, which can be also applied for a single phase induction motor or literally for any type of AC motor. When it comes to controlling the speed of induction motors, normally matrix converters are employed, involving many complex […]
How to Design an Uninterruptible Power Supply (UPS) Circuit
In this brief tutorial I have explained how to design a customized UPS circuit at home using ordinary components such as a few NAND ICs and a some relays. What is an UPS UPS which stands for uninterruptible power supply are inverters designed to provide a seamless AC mains power to a connected load without […]
Temperature Controlled DC Fan Circuits
Have you ever turned up your amplifier all the way, either at a party or just for fun? You may have noticed that “it gets hot” and thought that a fan would be useful. However, at low listening levels, you can hear the fan running. With this circuit, the fan will be automatically controlled by […]
