The motion sensor circuit explained in the article works by using doppler shift principle, in which the moving target is detected through the continuously varying frequency, reflected from the moving object. What is Doppler Effect One very fascinating feature of sound is the Doppler effect. The Doppler effect happens when the source that is producing […]
Archives for 2020
Precision Current Sensing and Monitoring Circuit using IC NCS21xR
If you are looking for current shunt monitors or current sense amplifiers then you have landed at the right page. Current shunt monitor is an instrumentation amplifier which senses the current across a shunt resistor in a system, and converts it into a logical signal output for triggering a switching device such a relay, transistor […]
Ultrasonic Fire Alarm Circuit using Air Turbulence Detection
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 […]
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 […]
Sine-Cosine Waveform Generator Circuit
The circuit discussed below is designed to generate precision sine and cosine waveforms, which are perfectly identical with their dimensions, but are 90° out of phase. There are a variety of applications which often demand a couple of sinewave frequencies which are of the identical frequency, but 90° out of phase. Simply put, a sine […]
LM10 Op Amp Application Circuits – Works with 1.1 V
The LM10 is a pioneering operational amplifier designed to operate from single ended power inputs with voltages as low as 1.1V, and up to as high as 40V. As can be witnessed in Figure 1, the device consists of an op amp, a precision 200 mV band-gap voltage reference, and a reference amplifier, all encased […]