Although transistors (BJTs) are popularly used for making amplifier circuits, these can be also effectively used for switching applications. A transistor switch is a circuit in which the collector of the transistor is switched ON/OFF with relatively larger current in response to a correspondingly switching low current ON/OFF signal at its base emitter. As an […]
Switch
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. […]
Whistle Activated Switch Circuit
In this post I have explained how to build a simple whistle sound operated relay circuit, which can be used for switching ON/OFF a 220 V load through whistle sounds. You can consider this circuit to be a whistle operated remote control circuit which will operate a connected load remotely through the sound of whistling. […]
Make this Thermo-Touch Operated Switch Circuit
The circuit explained here employs a rather different approach for implementing a touch operated switch action. Here instead of the resistance, the warmth of the finger is used for sensing and operating the circuit’s output. Irrespective of the ambient conditions, our hands and fingers mostly exhibits some extra warmth or increase in the level of […]
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 […]
Mains AC Current Detector Switch Circuit
The circuit I have I have explained in this article allows one to detect the current consumed by a device and to power one or more other devices accordingly. Indeed, the solution of a switchboard is not always applicable because it is often not very practical. Furthermore, some devices such as computers only start when […]