The 555 Timer shown below is configured as an 555 Astable Multivibrator previously discussed. However additional components have been added to enhance the operation of the circuit. As soon as the circuit is powered up the 555 will begin producing a square wave determined by the value of Capacitor C1 and Resistors R1 and R2, as determined by the ti
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ming equation below. This particular circuit uses a few additional [optional] components to allow for adjustment or compensation for variations in the tolerance of the timing capacitor [C1]. The 555 Integrated Circuit is an extremely accurate device. However it`s output is only as accurate or stable as the external components used. Standard value resistors normally come with a tolerance of either 1% or 5%, of course other resistor tolerances are available. For more information refer to Resistor Values, Tolerance and Package Sizes. Capacitors on the other hand came in a large variety of tolerances which could change by the quality of the part or by the dielectric used. There are three common capacitor types used with a 555 times, Ceramic, Tantalum, and Electrolytic dielectric. However regardless of the style used, the best tolerance value will be in the range of 10 to 20%. Also see Capacitor Dielectric Materials and their characteristics. A potentiometer [R3] can be placed on the Threshold pin to adjust the 2/3 Vcc line [recall that the potentiometer will be in parallel with the bottom two 5k resistors]. This effectively changes the trip point of the internal resistor ladder. The additional potentiometer can be used to change the trigger point and be used to compensate for variations in the Trigger Capacitor [C1]. As each new circuit is fabricated and a different capacitor used the potentiometer can be changed to adjust the...
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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