The simple ultrasonic fire alarm circuit I have explained below detects a fire hazard situation by picking up the variations in the surrounding air waves, or the air turbulence. The high sensitivity of the circuit ensures that even the slightest of air turbulence created by a temperature difference or fire is quickly detected and an […]
Newly Updated Circuit Projects:
Series 2S, 5S Li-Ion Cell Charger using BQ7718
This BQ7718 series 2S to 5S series Li-Ion cell charger is designed to monitor the voltage of each of the li-ion cells independently, with reference to an internally set reference level. As soon as any of the cell voltage tends to go above the reference level, it triggers an internal delay timer. This delay timer […]
Alarm Signal Generator IC ZSD100 Datasheet, Application
The ZSD100 is an alarm frequency generator IC which incorporates a frequency swept alarm signal generator designed solely for fixed and vehicle protection alarm systems. Circuit Operation For acquiring the specified alarm sound from this IC, just a single ZSD100, two timing capacitors, an in-expensive TO92 darlington, piezo transducer and coupling transformer is everything that […]
Loop-Alarm Circuits – Closed-Loop, Parallel-Loop, Series/Parallel-Loop
In this article I have explained a few simple loop based security alarm circuits, categorized under closed loop, parallel loop, and series/parallel loop. All these designs could be customized and used for a variety of security alarm applications. Overview In a loop alarm circuit, more than one sensor is used, each one wired with a […]
Ni-Cd Low Battery Monitor Circuit using Lambda Diode
The main feature of this lambda-diode low battery indicator for Ni-Cd batteries is that, the circuit itself consumes almost zero current, until the set low threshold level is reached and the indicator LED is illuminated. This feature makes the circuit very suitable for many low voltage battery operated systems, like radios, watches, timers, alarms, remote […]
Rechargeable LED Lantern Circuit Using Dynamo
In this post we study a simple rechargeable LED lantern circuit which features battery charging option from a dynamo as well as from a mains 220V source. The idea was requested by Mr. Chidimonday. Technical Specifications I like what you doing here, i have even put in work some of your circuit and it functioned […]