# Hobbyist & DIY Electronic Devices &amp; Circuits

### 100 + 100 Watt Car Stereo Amplifier Circuit Diagram Using IC STK4231 - Construction Explained

With monolithic linear ICs becoming commonly available, making monster power audio equipment at home has today become a child’s play. One such device STK4221 from SANYO can be simply used for different massive power audio amplifier applications. One sample circuit is discussed herein.

### How to Build a Switch Mode Power Supply Circuit - SMPS

The IC FAN7602B from FAIRCHILD is equipped with features which enables a fail proof and an efficient SMPS circuit design for green current-mode converters applications. The article includes complete schematic as well the transformer winding details of the circuit.

### What is Meant by the Beta of a Bipolar Junction Transistor

Ever wondered why only transistors are attributed with the property of current amplification? Basically it’s called the forward current gain or the hFE which is responsible for the amplification factor in transistors. Here, we discuss this in details and also learn how to build a hFE tester.

### How to Evaluate Common-Emitter Configuration in Bipolar Junction Transistors or BJTs

Bipolar junction transistors (BJTs) are probably the most extensively used devices in electronic circuits and within the ICs, and the most common configuration which are employed with them is the common-emitter mode. Here we find out how it’s evaluated using derived formulas and circuit diagrams.

### How to Calculate the Values of Current, Voltage, and Resistance in a Circuit?

The article explains, through easy steps, methods of calculating the values of current, voltage, reactance, and resistance in electrical or electronic circuits which may involve capacitors, inductors, resistors etc.

### How to Build a High Quality LED Digital Clock

A bright shiny digital LED clock display over the wall would certainly help to enhance the beauty of your house, and what if this digital clock is built by you? Wouldn’t it simply glorify your efforts? The entire building procedure of this digital clock is explained through circuit schematics.

### How to Make a Simple Radio Using the IC ZN 415

Normally, making a radio set at home may look quite a tedious affair due to the involvement of a high number of components; however a tiny candidate in the form of IC ZN 415 makes the procedures amazingly simple as it requires just a few ordinary parts for creating a complete radio.

### How to Build Small, Simple Audio Amplifiers Using IC LM386

You may find this circuit idea very handy particularly while making small projects involving low power audio amplifiers like door bells, pocket radios etc. The use of the popular chip LM386 makes the procedure very simple as it requires only a few external parts to make the amplifier function.

### Conducting Electrical House Wiring: Easy Tips & Layouts

The article provides some easy clues regarding conducting house electrical wiring. A few important tips if followed correctly can make the procedures really simple and without complexities.

### How to Control the Speed of a DC Motor Using IC L165

The article explains how to control the speed of a DC motor through a very straightforward and easy to build electronic circuit. The circuit utilizes just a single chip L165, making the control procedures rather simple to operate.