This presented refrigerator door open alarm circuit which alerts you after a period of time whenever your refrigerator door is left open. This circuit becomes very handy, because in case the door is left due to carelessness may cause significant increase in the consumption and affect the life of the fridge. Circuit Operation This circuit […]
Newly Updated Circuit Projects:
0 to 99 Digital Pulse Counter Circuit Diagrams
The proposed 00-99 digital pulse counter circuit becomes very handy in places where you need to keep the people organized in some specified order. Operating details of the digital counter As may be referred the circuit employs the popular 555 IC to genearte the pulse clocks. The pulse counting is done with the help of […]
Temperature Triggered DC Fan Speed Controller
This fan speed controller works by sensing the temperature of the engine and is accordingly used for the triggering. As the temperature increases so does the speed of the fan motor and vice versa. Circuit Operation Operation of the proposed temperature controlled fan may be understood as follows: The speed of the DC motor alters […]
Temperature to Voltage Converter Circuit
In this post I have explained a simple temperature to voltage converter circuit using IC LM317. The idea was requested by one of the dedicated members of this blog. Technical Specifications I have eurotherm TS200A temperature controller.this is thyrister based. This required 0-5V control voltage. I want one temperature control circuit when temperature is 25deg […]
Analogue Water Flow Sensor/Meter Circuit – Check Water Flow Rate
In this post I have explained a simple water flow meter/sensor circuit using hall effect sensor and a pulse counter circuit. Referring to the diagram shown below, we can see an arrangement consisting of a circular enclosure having a couple of pipes drilled in and a circular turbine shaped wheel installed inside the enclosure. How […]
How to Make a Barcode Security Lock Circuit
A simple barcode security lock circuit or barcode scanner circuit is explained in the following article using just a handful of ordinary components such as an op amp, an LDR and an laser light. We all have seen and are familiar with these arrays of thick and thin lines which can be seen printed on […]