Spectacular Spectra

Every electronics enthusiast dreams of making a hi-fi deck at least once in his life time. While he dreams, he plans, “the deck set will have excellent sound quality and wattage. It will be equipped with a 10-band graphic equaliser. Each band of the graphic equaliser will be accompanied by a IQ-level spectrum analyser. And when lights in the ten bands of the spectrum analyser will dance with the beats of drum and throbs of cymbals, what a great display will it be! «But when becomes back to reality and faces the great expenses involved, he has to omit a

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SMART GUY

The debut of self-adjusting studio lights.

We often describe studio lighting with words like «bright» or «rugged.» Now, we frequently find ourselves adding the word «smart.»

Quantum Instruments’ most recent LED ring lights, the Omicron OM3 and OM4 ($698 and $689, street), feature Auto Lighting Track (ALT). With the help of a built-in lightmeter, ALT dims or brightens Omicron output as a subject moves toward or away from the light. Because LED ring light output falls off rather rapidly, working distances are fairly shallow, and the brightening and dimming is often subtle. ALT does, however, noticeably expand a subject’s freedom

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Digital capacitance meter.

This device is an analog device, converted into a more compact version of the battery-powered. He has 8 years used to repair TVs and showed itself at its best. The instrument used in CMOS chips that have many «gathering dust» in the old stocks. This, and the use of the LCD display IZHTS5-4 / 8 allowed to bring the device current consumption to 10 mA and nourish it from the battery «Krona». Unit dimensions (with a few tricks) allow to place it in the body of the meter «D-830» or the like.

On DA1 and DA2 chips assembled converter «capacity-time»

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Stereo headphone audio amp on AD822AN

The amplifier is designed for use with stereo headphones. This audio amp is economical, can be operated from a single low-voltage power supply and at the same time has good technical characteristics. Total harmonic distortion of output signal span at 300 mV (peak to peak) at a frequency of 1 kHz is 0.079% (-62 dB with noise).

Stereo channels are input via the separating nonpolar capacitors C1 and C2. Voltage divider resistors R1-R2 and R3-R4 at the noninverting input circuits are chosen so that the outputs of op amp present voltage (1.5 V) equal to half the supply. The gain

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HP OFFICEJET PRO X551DW

Built to last, HP’s latest office-centric inkjet printer delivers stunning color for less

Consumers may have embraced the concept of feature-rich, multifunction inkjet printers whose replacement ink is more expensive than buying a whole new unit, but this isn’t an ideal scenario for businesses that require sturdier hardware capable of pumping out a high volume of pages each month. HP comes to the rescue with the OfficeJet Pro X551dw, delivering professional-quality output far more robust than low-end inkjets, while offering twice the speed and half the cost of comparable color laser printers. It’s also built to handle up to 75,000

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Hit The Target

An Electronic Game

Video games are very popular in urban area, even though video game equipment are very exclusive and expensive. The constructional details of an electronic shooting game are described here. It employs a minimum number of low-cost and easily available components, and has all the actual functions of electronic games. In place of video screen, this project uses an LED display.

Theme of the game

Shooting down a fast moving object in the sky is not easy. Here a number of military aeroplanes appear at different positions for very short durations. All the aircraft are green except one

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Full Featured Touch Control Programmable Power Supply

Touch control of electronic gadgets is no longer a dream. Almost all electronic hobbyists have their own power supply using the most common IC regulator LM317. They may have a selectable rotary switch to select a particular output or a potentiometer to vary the output smoothly.

Here is a circuit which will change the output of the power supply by a slight touch of the finger! Those who have a power supply can just add this feature while those who do not have one may construct it fully as presented here.

The circuit

The logic of the circuit is very

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AM/FM Radio Receiver using BEL7220

The BEL, 7220 is an integrated AM/FM IC designed for economical and high quality receivers. The BEL

7220 IC can be used in battery or mains operated AM/FM receivers working from a nominal voltage of 1.6 to 6 volts. The functional block diagram is shown in Fig.l. With the exception of FM front end and audio output stage, the following functions are integrated.

(a) Pre-amplifier and double balanced mixer with AGC

(b) One pin local oscillator

(c) IF amplifier with internal AGC

(d) FM/IF amplifier and limiter

(e) Detector

(f) FM quadrature detector

(g) Audio pre-amplifier

The audio power amplifier

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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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Digital Volume Control

Most modern TVs and VCRs have a digital volume control for either incrementing or decrementing the volume. In digital control you have to press a switch instead of rotating a knob like in old sets. This versatile digital volume control circuit can be used for tape recorders, amplifiers. TVs etc.

In the circuit IC 555 is used as an a stable multivibrator, which produces a clock pulse of 11 Hz frequency at pin 3. I’his clock pulse is fed to the counter (IC 4510) through a combination of gales. Normally. N1 and N2 will not allow any clock pulse because

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