Several circuits of musical car horn have been published in BEP but “Double tune car reverse horn” differs from them. Projects like this helps you to get more used to various electronic devices. The circuit that produces the double tune car reverse horn generates two types of sounds: one is a pleasant ‘ding-dong’ bell sound and the other one is a sweet chirping sound of a bird. Here, the IC HT82D (IC1) is used as the sound generator whose operating voltage range is 2 to 5 volts. It has 10…
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Simple Power Supply Resumption Alarm
Once again the most popular timer IC NE555 proved that its applications are limited only to the user’s ingenuity. The circuit of the simple power resumption alarm shown here is straightforward, where IC1 is wired in a special kind of mode. Circuit Description of Simple Power Supply Resumption Alarm When the power supply resumes, pin 2 of IC1 is grounded through C1 and pin 3 goes high. This makes reset pin 4 go high for about 10 seconds. When the capacitor C1 charges to two-thirds of the supply voltage, the output…
Read MoreRain Sound Generator Circuit
The project described here is of “Rain Sound Generator Circuit” which is simple and uses ordinary components. It comprises two oscillators: one is a variable low-frequency oscillator that uses UJT 2N2646 (T1) and the other one uses timer IC NE555. A single UJT (Unijunction Transistor) can be oscillated without using a tank coil. The electrical characteristics of UJT are quite different from ordinary bipolar transistors. The second oscillator using timer IC NE555, IC1 is in astable mode. Here, T1 acts as the noise generator for the circuit. The sound produced…
Read MoreSteam Whistle Circuit using 741 IC
The project “Steam Whistle Circuit using 741 IC” produces a sound similar to that of a steam locomotive whistle. Here, in the circuit Transistor T1 and T2 from a multivibrator, the frequency of which is set by preset VR3. This is the ‘toot’ part of the whistle. Transistor T4 amplifies white noise generated across the reverse-biased transistor T3. White noise and toot mixed by IC1. The ratio of these is set by preset VR2. IC1 is the most popular and low-cost IC 741 and is used as a low-frequency multivibrator,…
Read MoreSimple Warning Alarm
The “Simple Warning Alarm” circuit is creatively designed, leveraging the abilities of a transistor to produce clear and easily audible alerts, like notifications or distinct sounds. Its flexibility allows it to effortlessly integrate with a wide arrangement of security devices, such as burglar alarms and fire alarms, offering a dependable auditory indication of the device’s operational status. This straightforward yet efficient solution not only enhances the overall effectiveness of security setups but also ensures that critical circumstances are promptly detected, making it an invaluable addition to any security-conscious environment. Description…
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