The timer circuit shown gives independent control of the output`s on and off intervals, which can range from 0. 055 seconds to 30 minutes, relatively unaffected by power-line transients. IC1 is a CMOS programmable-timer chip that includes 24 ripple-binary counter stages; the first eight are bypassed when logic 1 is applied to pin 6. Then, a4-bit in
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put code at pins A, B, C, and D connects one of the 16 remaining stages to the output at pin 13. The chip includes an oscillator whose timing components are CT, RT1, and RT2. _For this example, you adjust RT2 for an internal period TlN of 54. 9 ms (18. 2 Hz). Then, the output on or off interval is: Tour= TIN2 N-1, where N is the number of counter stages in the internal divider chain (See Fig. 110-3). IC2 and IC3 are CMOS triple-spdt analog switches that connect one BCD code (A1 -D1) for the on interval and another (A2-D2) for the off interval. You can apply the codes using manual toggle switches or programmable latches. When power is first applied, the switches are in the positions shown, which applies A1 -D1 to IC1 and generates the on intervat. When the output changes state, all the switches change position and initiate the off interval by applying, 42-D2 to IC1. The cycle then repeats. To eliminate race conditions, switches S1 and S2 of IC3 operate in sequence before the remaining four switches operate in parallel. To start the output sequence with an off instead of an on interval, connect a power-on-set signal at pin 1 instead of the power-on-reset signal at pin 2.
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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