Timing interval is initiated by applying power, and is determined by RT-CT. At end of interval, unijunction transistor triggers silicon controlled rectifier, to apply essentially full supply voltage to load. Delay range is from 0. 4millisec to 1 minute. - Transistor Manual, Seventh Edition, General Electric Co. 1964, p 321. (View) Addition of silico
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n unijunction transistor Q3 to conventional mono stable mvbr expands time delay two orders of magnitude. -M. P. Humblet, Unijunction Transistor Multiplies Monostable `s Pulsewidth, Electronics, 35:26, p 74-75. (View) This simple circuit acts as a frequency multiplier, which converts any sloped input waveform into a distorted output waveform, whose frequency spectrum is marked by a rich harmonics content. The input frequency does not disappear from the spectrum, however. When a pure sine-wave input signal is applied, the circuit generates odd harmonics only. The push-pull outputs of comparators IC1b and IC1a then supply differential signals to adder IC2, which cancels out even-numbered harmonics. For different mark/space ratios of the output signals, as set with P1 and P2, the harmonic spectrum changes. A duty factor of 0. 25, for instance, will cause the circuit to supply the second, sixth, and tenth harmonics, but not the fourth one. The spectrum function is then written as sin x/x. The reference levels for the input comparators determine the output waveform. The desired degree of distortion of the input waveform is, therefore, adjusted with the two presets. R2 and R3 should be matched to within 1 percent. (View) Feedback from collector to base of power transistor through C1 and R2 protects device from destructive transients generated when inductive load such as solenoid is turned off. Alternative use of diode CR2 or...
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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