Beat frequency indicators are used to indicate whenever frequency of a signal of our interest exceeds reference frequency. This is one such indicator circuit which uses LED’s to indicate when our signal exceeds the reference frequency. These indicator circuits can… Read more
Audio amplifiers are commonly used to amplify low power audio signals such as the signal from a radio receiver or microphone so that it can be used to drive loudspeakers or headphones. Commercially available amplifiers can be very expensive. So… Read more
Spy Bug circuits are something that’s used when we need to listen to conversation without being noticed or to simply put to spy on a person. Generally Spy bug circuits are constructed using a Mic, amplifier and speaker. The medium… Read more
Everyone loves music and some have the habit of wearing their headphones all the time listening to cool music. For those music fanatics this headphone amplifier circuit will be a great hobby build since it delivers amplified mind blowing music… Read more
Musical greeting cards are quite popular during special occasions all around the world and we all would have presented this thing to our dear ones before. But have you ever tried making one by your own? if not, its time… Read more
Melody/Music circuits are used in greeting cards, door bells, alarms etc and in each of these applications we are acquiring different music as output. Ever wondered how? and would you believe if i say that all the above applications… Read more
Siren Circuit using simple Transistors The above given was a simple Siren Circuit diagram using transistors which can be built and implemented by means of low cost. The basic principle behind siren circuits are producing waveforms which differ in frequency… Read more