The following simple analogue frequency meter circuits can be used for measuring frequencies which may be either sine wave or square wave. The input frequency which is to be measured must be at least 25 mV RMS, for optimal detection and measurement. The design facilitates a relatively wide range of frequency measurement, right from 10 […]
Simple
Simple Mini Audio Amplifier Circuits
In this article we are discussing a handful of simple, mini audio amplifier circuits which can be built quickly for amplifying very tiny input signals into audible speaker outputs. 1) 1 Watt Amplifier Circuit The first simple mini audio amplifier circuit works with a ‘complementary’ output stage, having a single NPN and a single PNP […]
Simple Low Dropout Regulator Circuits Explained
The transistorized low dropout voltage regulator circuit ideas explained in the following article can be used for getting stabilized output voltages right from 3 V and above, such as 5 V, 8 V, 9 V, 12 V, etc with an extremely low dropout of 0.1 V. For example, if you make the proposed 5 V […]
Simple Digital Timer Circuit with 2 Digit Display
This simple digital timer circuit can be used to obtain timing output through selectable ranges, which can be set from 0 to 99 second, with 1 second interval, 0 to 990 seconds with 10 second interval, and 0 to 99 minutes with 1 minute interval. All these timing outputs can be visualized and tracked through […]
Simple Touch Operated Potentiometer Circuit
In this touch operated potentiometer circuit we have two touch pads, which produce a slowly increasing voltage at the output when one touch pad is touched, and a decreasing voltage when the other touch pad is touched. When the touch contact is removed the voltage holds at that particular increased or decreased level “permanently”. Touch […]
Listen to UHF and SHF (GHz) Bands with this Simple Circuit
This simple two IC circuit can be used for capturing and listening to frequencies in the GHz range. Receivers designed to cover frequencies as high as several gigahertz (which is many thousand MHz!) are generally difficult to find, specifically for anyone who is looking for cheap versions of these gadgets. However, it may be possible […]




