The proposed LED sound level meter will detect the sound hitting the MIC, and indicate its volume level through an array of LED, connected as a bar graph. Circuit Description […]
Simple Crystal Tester Circuit
The proposed simple crystal tester circuit can be used for accurately testing the operating frequency of any standard crystal, quickly. The figure below shows a crystal checker circuit schematic. In […]
Loudspeaker Power Indicator Circuit
This circuit will reveal the height level of an input signal placed on a speaker. It is mainly meant as a fool proof device when linked to an amplifier of […]
3 LED Battery Monitor Circuit
This battery monitor circuit can be used to monitor the charge level of a battery in 3 different steps, indicated by 3 separate LEDs. Just three LEDs are incorporated to […]
LED Voltage Monitor Circuit
A well balanced power supply is completely necessary for the precise functioning of computers and TTL circuits. A voltage fluctuation of 10% is undoubtedly not bearable, it is therefore advisable […]
220 V LED Indicator Circuit
This LED circuit can be used to indicate the presence of 220 V mains AC supply, without using a transformer. The long life of LEDs make them extremely appropriate for […]