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. […]
Relay
Thermostat Delay Relay Timer Circuit
The circuit given below describes a time delay relay system which is used for keeping a hot air blower working under a specifically programmed timing sequence. The idea was requested by Mr. Doug Shadix, I have explained more: Technical Specifications Hi Swagatam,Looks like you know your stuff when it comes to these timer circuits, this one […]
Transformerless Relay Driver Stage
In this post I have explained an enhanced transformerles power supply circuit design which consists a well stabilized and regulated DC stage along with a relay driver stage which operates through an external pulse. he idea was suggested by Mr. Reza. Technical Specifications Reza: Dear Sir, I have a problem with one Circuit regarding converting […]
ON/OFF Relay Switch Circuit using Reflection Sensor
This 220 V ON/OFF electronic relay switch can be toggled ON/OFF simply by alternately bringing your finger close to the reflection sensor CNY70. About CNY70 CNY70 is an infrared reflecting sensor comprised of an infrared emitting diode and a phototransistor housed in a tiny plastic container. The sensor operates by generating infrared light and sensing […]
Transistor Relay Driver Circuit with Formula and Calculations
In this article we will comprehensively study a transistor relay driver circuit and learn how to design its configuration by calculating the parameters through formulas. Importance of Relay Relays are one of the most important components in electronic circuits. Especially in circuits where high power transfer or mains AC load switching is involved, relays play […]
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 […]





