### FREQUENCY MODULATION (FM) BROADCASTING BASIC TUTORIALS

WHAT IS FREQUENCY MODULATION (FM) BROADCASTING?

The monophonic system of FM broadcasting was developed to allow sound transmission of voice and music for reception by the general public for audio frequencies from 50 to 15,000 Hz, all to be contained within a +/−75-kHz RF bandwidth.

### LEAD ACID BATTERY CHARGER CIRCUIT BASIC ELECTRONICS PROJECT

CIRCUIT ON HOW TO MAKE LEAD ACID BATTERY CHARGER?

This is a basic electronic project on how to make a Lead Acid Battery Charger. The circuit can be seen below:

Thic circuit furnishes an initial voltage of 2.5 Volts per cell at 25 degrees celcius to rapidly charge a battery. The LM301A compares the voltage drop across R1 with an mV referenced set by R2.

### ELECTROSCOPE DEFINITION BASICS AND TUTORIALS

WHAT IS AN ELECTROSCOPE?

The Electroscope.  It has been shown experimentally that an electric charge can be detected because it attracts light objects such as pith balls, bits of paper, etc.

Any device used for detecting electric charges is called an electroscope.  In its simplest form, an electroscope consists of a pith ball hanging on the end of a silk thread.  By touching it with a body of a known charge, you have an instrument that can detect charged bodies and that can indicate the type of charge (polarity).

### SINE WAVE GENERATOR ELECTRONIC PROJECT CIRCUIT

HOW TO MAKE SINE WAVE GENERATOR?

Many electronic devices depend upon the shape of the signals. It is very easy to produce
squarewave signals from sine wave, but reproducing sinewave signals from the square wave is quite difficult.

In case of static squarewave-to-sinewave converter, in low frequency range, we can get accurate sine wave, but in high frequency range the shape will not be a true sine wave. Here is a solution to that problem.

### COMMONLY USED IC COUNTERS AND REGISTERS BELONGING TO TTL CMOS & ECL LOGIC FAMILIES

A Table of Commonly used IC counters and registers belonging to the TTL, CMOS and ECL logic families

Type Number Function Logic FAMILY

7491 Eight-bit shift register (serial-in/serial-out) TTL
7493 Four-bit binary counter TTL
74160 BCD decade counter with asynchronous CLEAR TTL
74161 Four-bit binary counter with asynchronous CLEAR TTL
74162 BCD decade counter with synchronous CLEAR TTL
74163 Four-bit binary counter with synchronous CLEAR TTL

### THYRISTORS DEFINITION AND BASIC INFORMATION TUTORIALS

WHAT ARE THYRISTORS? INFORMATION ABOUT THYRISTORS

Thyristors (or silicon controlled rectifiers) are three-terminal devices which can be used for switching and a.c. power control. Thyristors can switch very rapidly from a conducting to a nonconducting state.

### SEMICONDUCTORS DEFINITION AND BASIC KNOWLEDGE

SEMICONDUCTORS BASIC INFORMATION
What Are Semiconductors?

Semiconductors are a category of materials with an electrical conductivity that is between that of conductors and insulators. Good conductors, which are all metals, have electrical resistivities down in the range of 10−6 -cm.

Insulators have electrical resistivities that are up in the range from 10^6 to as much as about 1012 -cm. Semiconductors have resistivities that are generally in the range of 10^−4 up to 10^ 4 ohm-cm. The resistivity of a semiconductor is strongly influenced by impurities, called dopants, that are purposely added to the material to change the electronic characteristics.

### HALF-DIPOLE ANTENNAS BASIC INFORMATION ELECTRONICS TUTORIALS

WHAT ARE HALF-DIPOLE ANTENNAS?

Developing a theory of antenna radiation requires many simplifications. Designing radiating antennas is not the aim of this book. Our interests relate to the field strengths of existing transmitters (interference), the fields that are inadvertently radiated by circuits and the impact of radiation that enters a circuit.

### VEHICLE SECURITY SYSTEM ALARM ELECTRONICS PROJECT

HOW TO MAKE A VEHICLE SECURITY SYSTEM ALARM?

This is a basic electronic project on how to make a vehicle security alarm system. Below is the schematic diagram. (click the photo to enlarge)

### 8051 FAMILY MICROCONTROLLER PROCESSOR ARCHITECTURE BASIC INFORMATION

THE 8051 FAMILY MICROCONTROLLER PROCESSOR ARCHITECTURE

You might wonder why the 8051 family of processors was chosen for this purpose, as it is a relatively old processor. If you read current technical journal articles, you might get the impression that all the action is in 32-bit micros.

That is primarily due to the fact that the companies that sell the high-end devices are working very hard to put their newest technology in front of their\ customers, and they are the ones who write most of the trade articles.

### TELEPHONE SET SYSTEM BASIC ELECTRONIC TUTORIALS

HOW A TELEPHONE WORKS? WHAT YOU NEED TO KNOW ABOUT THE TELEPHONE

The telephone arrived as a practical instrument over a century ago in 1876, an outgrowth of experiments on a device to send multiple telegraph signals over a single wire. Alexander Graham Bell, a native of Scotland, while conducting electrical experiments spilled acid on his trousers.

His reaction, the now-famous “Mr. Watson, come here, I want you,” brought Thomas A. Watson on the run not only because of his employer‘s distress, but because the words had been carried by electricity into Watson’s room and reproduced clearly on his receiving set.

### EVOLUTION OF MICROPROCESSORS TUTORIALS

WHAT IS THE EVOLUTION OF MICROPROCESSORS?

The evolution of microprocessors has been known to follow Moore’s law, which suggests that the complexity of an integrated circuit, with respect to the minimum component cost, doubles every 24 months.

This rule has been generally followed, since the humble beginning of microprocessors as the drivers for calculators to the present-day scenario where every system, from the largest mainframes to the smallest handheld computers, uses a microprocessor at its core.

### SIMPLE ELECTRONIC ORGAN PROJECT

HOW TO MAKE A SIMPLE ELECTRONIC ORGAN?

It uses the popular NE555 integrated circuit, which contains a circuit which will periodically switch the voltage on the output pin between the supply voltage and zero. Just how frequently this switching occurs depends upon the components external to the integrated circuit.

If this switching occurs several hundred or thousand times a second, the change in voltage produced will generate a musical note when connected to a small loudspeaker. The circuit is shown below:

### GAS LEAKAGE ALARM ELECTRONICS PROJECT

HOW TO MAKE A GAS LEAKAGE ALARM?

This is a basic electronic project of Gas Leakage Alarm, using a SEN-1327. The circuit diagram below shows the circuit of the gas leakage alarm. The circuit operates off a 9V PP3 battery. Zener diode ZD1 is used to convert 9V into 5V DC to drive the gas sensor module.

### COAXIAL CABLE POWER RATINGS BASIC INFORMATION

POWER RATINGS OF COAXIAL CABLES

Power Rating
Both peak and average power ratings are required to fully describe the capabilities of a transmission line. In most applications, the peak power rating limits the low frequency or pulse energy, and the average power rating limits high-frequency applications, as shown in Fig. 4.4.

### 2M RECEIVER PRE AMPLIFIER ELECTORNIC PROJECT

HOW TO MAKE 2M RECEIVER PRE AMPLIFIER?

Designed specifically to complement the modified air-band portable (also described in this series), this can be used with some success on many receivers suffering from ‘deafness’ on VHF.

The circuit
An RF preamplifier is a device which improves the input signal to an existing receiver, enabling it to work more effectively. Because of the noise which is added to the signal by the preamplifier, very weak signals may not be usefully enhanced, but stronger signals will be improved considerably.

### ASCII CODE TUTORIALS

WHAT IS THE ASCII CODE?

The ASCII (American Standard Code for Information Interchange), pronounced ‘ask-ee’, is strictly a seven-bit code based on the English alphabet. ASCII codes are used to represent alphanumeric data in computers, communications equipment and other related devices. The code was first published as a standard in 1967.

### PACKED AND UNPACKED BINARY CODED DECIMAL (BCD) NUMBERS

WHAT ARE PACKED AND UNPACKED BINARY CODED DECIMAL (BCD) NUMBERS

In the case of unpacked BCD numbers, each four-bit BCD group corresponding to a decimal digit is stored in a separate register inside the machine. In such a case, if the registers are eight bits or wider, the register space is wasted.