POWER STORAGE DETAILS

POWER STORAGE DETAILS

Block diagram:

The voltage generated by the source (generator) is not of pure dc. This has to be

rectified before storage. A diode rectifier then provides a full-wave rectified voltage that is

initially filtered by a simple capacitor filter to produce a dc voltage.

Block diagram (Power supply)

Working principle:

The Full Wave Bridge Rectifier

Full Wave Bridge Rectifier uses four individual rectifying diodes connected in a

closed-loop "bridge" configuration to produce the desired output. The main advantage of this

a bridge circuit is that it does not require a special center-tapped transformer, thereby reducing

its size and cost.

The single secondary winding is connected to one side of the diode bridge network

and the load to the other side as shown below.

The Diode Bridge Rectifier

The four diodes labeled D1 to D4 are arranged in “series pairs” with only two diodes

conducting current during each half cycle. During the positive half cycle of the supply.

diodes DI and D2 conduct in series while diodes D3 and D4 are reverse biased and the

current flows through the load as shown below.

The Positive Half-cycle

During the negative half the cycle of the supply, diodes D3, and D4 conduct in series, but

diodes D1 and D2switch "OFF" as they are now reverse biased. The current flowing through

the load is the same direction as before.

The Negative Half-cycle

As the current flowing through the load is unidirectional, so the voltage developed

across the load is also unidirectional. The average DC voltage across the load is 0.637 VMAX.

However in reality, during each half cycle the current flows through two diodes instead of

just one so the amplitude of the output voltage is two voltage drops (2 x 0.7 = 1.4V ) less

then the input VMAX amplitude. The ripple frequency is now twice the supply frequency (eg.

100Hz for a 50Hz supply)

 Typical Bridge Rectifier

             Although we can use 4  individual power diodes to make a full-wave bridge

rectifier, pre-made bridge rectifier components are available "off-the-shelf" in a range of

different voltage and current sizes that can be soldered directly into a PCB circuit board or be

connected by spade connectors.

The Smoothing Capacitor

           We saw in the previous section that the single-phase half-wave rectifier produces an

output wave every half cycle and that it was not practical to use this type of circuit to produce

a steady DC supply.

The full-wave bridge rectifier, however, gives us a greater mean DC value (0.637

Vmax) with less superimposed ripple while the output waveform is twice that of the

frequency of the input supply frequency

We can therefore increase its average DC output level even higher by connecting a

Suitable smoothing capacitor across the output of the bridge circuit as shown below.

Full-wave Rectifier with Smoothing Capacitor

The smoothing capacitor converts the full-wave rippled output of the rectifier into a

smooth DC output voltage. Generally for the DC power supply circuit the smoothing capacitor

is an Aluminium Electrolytic the type that has a capacitance value of 100uF or more with

repeated DC voltage pulses from the rectifier charging up the capacitor to the peak

However, there are two important parameters to consider when choosing a suitable

smoothing capacitor and these are its Working Voltage, which must be higher than the

Ipad output value of the rectifier and its Capacitance Value, which determines the amount of

a ripple that will appear superimposed on top of the DC voltage.

Too low a capacitance value and the capacitor has little effect on the output

But if the smoothing the capacitor is sufficiently large enough (parallel capacitor can

he used) and the load current is not too the output voltage will be almost as smooth as

pure DC. As a general rule of thumb, we are looking to have a ripple voltage of less than

peak to

The rectified filtered output voltage is then stored in a battery. The battery charging

time is based on the power generated by the source.

ATMEL 89S52 MICROCONTROLLER

FEATURES:

·         Compatible with MCS0-51 Products

·         8K Bytes of In-System Programmable (ISP) Flash Memory

·         Endurance: 10.000 Write/Erase Cycles

·         4.0 to 5.5V Operating Range

·         Fully Static Operation: 0 Hz to 33 MHZ

·         Three-level Program Memory Lock

·         256 x 8-bit Internal RAM

·         32 Programmable I/O Lines

·         Three 16-bit Timer/Counters

·         Eight InterRupt Sources

·         Full Duplex UART Serial Channel

PIN CONFIGURATION:

DUAL IN-LINE PACKAGE PIN FUNCTIONS:

 Pin Configuration:

VSS (Pin No: 20) Ground: 0 V reference.

VCC (Pin No: 40) Power Supply: This is the power supply voltage for normal, idle, and

power-down operation.

PORT REGISTERS:

There are 4 Input/output ports named PO. PL. P2 and P3, Data must be written into

port registers first to send it out to any other external device through ports. Similarly, any data

received through ports must be read from port registers for performing any operation. All 4

port registers are a bit as well as byte-addressable.

Port 0 pins may serve as inputs, outputs, or when used together as a bi-directional

low order address and data bus for external memory

Port 1 has no dual functions. It works as an I/O port only.

Port 2 may be used as an input/output port similar in operation to port 1. The alternate

use of port 2 is to supply a high-order address byte in conjunction with the port 0 low-order

byte to address external memory

Port 3 is an input/output port similar to port 1. The port 3 alternate uses are shown in

the following table:

PIN	ALTERNATE USE
P3.0-RXD	Serial data input
P3.1-TXD	Serial data output
P3.2-INTO	External interrupt 0
P3.3-INT1	External interrupt 1
P3.4-TO	External timer 0 input
P3.5-T1	External timer1 input
P3.6-WR	External memory write pulse
P3.7-RD	External memory read pulse

Reset: Pin 9

A high on this pin for two machine cycles while the oscillator is running resets the

device. To insure a good power on reset, the RST pin must be high long enough to allow the

oscillator time to start up (normally a few milliseconds) plus two machine eyeles. At power

on the voltage on VCC and RST must come up at the same time for a proper start-up. Ports

1.2. and 3 will asynchronously be driven to their reset condition when a voltage above VIHI

(min.) is applied to RESET.

An internal resistor to VSS permits a power on reset using only an external capacitor

to VCC

Between XIAOMI and XTAL2, A 11.0592MHZ is connected.