Variable Speed Multi-Output Running Mode LED Display

The circuit is a transistor transistor-logic (TTL) compatible running light display with a maximum of 15 outputs and is capable of driving up to 751 LEDs for display. The circuitry employs TTL devices and ICs. Power dissipation of the logic circuit is in milliwatts.

The circuit is based on digital logic having 4 inputs (hexadecimal) and 15 outputs which drive the output transistors. This logic circuit consists of six ICs — three quad 2-input OR gates and three quad 2-input AND. gates.

If A, B, C and D arc the inputs to this logic circuit and Y1, Y2, Y3 Y15

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The Universal Timer

The timing of events and processes is becoming an ever increasing necessity in virtually every automation task, not only in the industrial sphere but even in the domestic sphere. No wonder timers arc often referred to as the first step towards automation.

This universal timer offers an ultrawide timing range which can be set with pin point precision anywhere from one-tenth of a second to hundred hours! Dispensing with the ever-problematic analogue dial, this timer is built around common CMOS chips, and features autolatch facility plus such a low current consumption (hat most multimeters would fail to detect it. All

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Stop motion animation, one of the oldest special effects, makes the impossible seem real. But the tedious process — move the model, take a picture, repeat thousands of times — discourages citizen film makers with non-obsessive patience levels.

I recently discovered iStopMotion, Mac software that automates the process and works with any camera that can capture QuickTime. iStopMotion features a transparent preview that lets you superimpose the previous frame over the current one before you shoot. This alone helps enormously. The Time Lapse feature shoots frames continuously at a specified interval, and Speech Recognition lets you say “Capture” instead of


Matt Prior

Tester’s notes

Skids. Drifts. Oversteer. Churlish, childish stuff that is inefficient, irresponsible, wears through tyres and slows cars down. All true. A colleague came back to the office the other day and reported that an industry test driver had told him one of the “problems” with car journalists is their obsession with going sideways. True, too, perhaps.

This driver, and the company he works for, likes cars that go fast. Flipping fast. If there’s too much lateral slip, too much looking out of the side window, too much smoking of tyre, with knuckles visible through the windscreen to amply demonstrate

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Increase the security of signaling systems.

Long experience of operating devices of automatic lock in areas with electric traction AC showed that the projects provided the protection device signaling short-circuit in the contact system is not always effective. The greatest impact of short circuits have on the signaling device in the winter and in areas with low conductivity of the soil.

Consider the most typical device failure signaling Short-circuit in the contact network.

Typical circuit power relay cabinet (RSH) signal installation of high-voltage line of automatic lock provides security features designed to protect the device from atmospheric signaling surge. Two stage low-voltage circuit grounding transformer

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Fuzz Effect Box For Guitarists

The ‘Fuzz’ sound is derived by clipping the input waveform, there by enriching the signal with odd harmonics which provide The harsh sound. This circuit produces a fuzz which gradually decays into a ‘clean signal’.

The circuit uses the standard op-amp 741 in non-inverting configuration. The gain of this amplifier is com rolled by the feedback network comprising VR1, R2 and R3.

Input signal from the guitar passes to the op-amp through DC blocking capacitor C1. Resistor Rl sets the input impedance at 100k, which suits most guitars, Resulting signals from the op-jimp are reduced in amplitude by the potential

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Fire Sensing System

Fire is one of the most hazardous natural forces. Sensing fire and fighting it in the early stages can prevent losses to a great extent. Sensing fire electronically has become one of the most reliable fire-fighting techniques today.

Sensing fire needs reliable smoke/ fire sensors. Thermistors can sense fire depending on temperature increase principle. We can also use opto devices to sense smoke. One of the projects published in EFY Vol.6 used Japanese Figaro TGS gas sensors. Such sensors are expensive and are not easily available.

The system presented here uses the most common yet very reliable bimetallic strip of

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Electronic Washing Machine Control

Nowadays, commercially available washing machines are provided with features like auto-off timer, reversible impeller etc. Most of them have mechanical timers, reversers etc. Some are equipped with electronic timers. But they are very expensive and out of reach of the average consumer.

Keeping this in view, I have designed an electronic washing machine control circuit. The circuit provides all the facilities provided by reputed companies and even more. The circuit has a timer circuit which can be set to any duration from 0 to 15 minutes and can be extended to any length of time by merely changing a capacitor.

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Electronic Switch Starter

This electronic switch starter provides some excellent facilities like overload and overvoltage protections, and auto-trip. Considering its small size and weight, as compared to that of conventional starters, it is far more attractive to use than the latter.

This starter has hardly any mechanical or moving part, except the relay, and is therefore very quick in sensing unfavourable conditions for the machinery to which it is connected. It trips the supply on sensing overload or overvoltage conditions.


For switching on the starter switch SI is pressed which energises the relay, thereby providing the supply to the circuitry as well

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Electronic Number Shooting Game

TV and video games have become very popular, both with children and grown-ups. These games provide good recreation as the animated figures make the player feel as if he is actually playing with another human being.

The circuit described here is the basic circuit for all electronic games of this kind. Once you assemble it only a little imagination is required to make other games.

In this circuit, costly and not easily available LCD panel is avoided and only LEDs are used for display- For low static power dissipation, fully CMOS ICs art used.

The game and how to play

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