The capability to determine which part of the tape is empty and which part has a recorded data can help accelerate your work of looking for a certain program. The circuit uses a tone decoder IC 567 and a timer IC 555. The 567 IC decodes the pilot tone of each recorded program. The tone frequency to which this tone decoder reacts must be set with p
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otentiometer P1. To do this, play a cassette with a recorded data and within the first 2 to 10 seconds try to adjust P1 so that LED D1 lights up. If you did not get it at the first try, rewind the tape and start again from the beginning. The input of the circuit is connected to the output of the cassette recorder. The signal from the tape reaches the inputs of the tone decoder 567 and the timer 555 simultaneously through capacitor C1. One of three things may possibly happen: First. No signal. The tone decoder 567 outputs a logic 1 (high) and the timer 555 outputs a logic 0 (low). IC 74145 activates decimal output 2. LED D2 lights up.
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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