# : Design and Implementation of a 500 Watts, 12d.C Volt/230a.C Volt Inverter with Overload Protection Capability

Topics: Alternating current, Direct current, Transistor Pages: 17 (4748 words) Published: August 3, 2012
INTRODUCTION
Background to the project
An inverter is an electronic device that has the ability to convert the direct current (dc) from the battery or solar cells (panels) to alternating current (ac) which is the convectional form that powers many electrical appliances. Most standard appliances are designed to accept only AC (alternating current) voltages because that's how electricity is supplied from the grid. To run an electronic device from a DC (direct current) source you obviously need to transform DC into AC. A device that converts electricity from DC form to AC form using electronic circuits is known in power industry as inverter. Sometimes, the same term is used in digital electronics for a circuit that switches the logic level of a signal. To avoid confusion, the device we are talking about is a power inverter. Its typical application is to convert a 12V battery voltage (direct current) into conventional residential voltage. Inverters are used in a wide variety of applications like small car adaptor to large grid-tie systems that can supply electricity to an office or even entire home.

Reasons and Problem leading to formulation of the project
In rural areas electric power is a problem, there is high degree of power cut-off or no electricity. This makes people in these areas face difficulties in using electronic equipment like mobile phones, radios etc. since most of appliances accept only AC (alternating current) voltages because that's how electricity is supplied from the grid. It is needed to design a mechanism which may resolve the problem, design and implementation of a 12vd.c/240va.c, 500watts power inverter with overload protection capability. Objectives of the Project

To design an oscillator that converts electricity from DC form to AC form using electronic circuits using a minimum number of components To design the driver circuit of those signal from the oscillator and amplify them. To make sure the voltage is stepped-up into about 240V ac.

To design the output of that inverter being able to produce 240V ac with high power output To implement the designed system

Specification of the required circuit system
Power inverter with the following Specification:
Input Voltage:12V D.C
Output Voltage Range: 220 – 230 V A.C
Output Frequency: 50Hz +/- 5Hz
Output Waveform: Modified Sine wave
Continuous Output Power: 500 Watt
Protections: Overload and Output short-circuit protection
Battery reverse polarity protection
High and Low voltage input shutdown

Significance of the Power Inverter
The power inverter is mainly used to convert direct current [12 volt] from car or solar battery to alternating current [230 volt]. With the help of this inverter, it will be possible to run various electrical appliances in our home when there is a power outage or interruption especially in rural areas.

User specification
Having the recharged car or solar battery, the user will be able to power the domestic appliances like bulbs, radio, charging mobile phones etc. The connected load at the output should be low less than 500watt for optimal operation. That is the larger the load is the more battery will get discharged in no time.

Functional Specification
Lights when inverter is overload, or short-circuited at the output and the output will be cut-off. Remove cause of overload, and press on to reset button.

Low voltage input Indicator
Lights when inverter input voltage from the battery is low to avoid excess discharge of the battery. And the inverter shuts down. High voltage input Indicator
Lights when inverter input voltage from the battery is high due to overcharge problem. This is to prevent from burn of the inverter and avoid high output voltage which can burn the connected load.

THEORY Theory of Important parts
A power inverter is an electrical device that...