kinetic energy to electrical energy

The kinetic energy of an object is the energy which it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes. The same amount of work is done by the body in decelerating from its current speed to a state of rest.

The kinetic energy in the moving cyclist and the bicycle can be converted to other forms. For example, the cyclist could encounter a hill just high enough to coast up, so that the bicycle comes to a complete halt at the top. The kinetic energy has now largely been converted to gravitational potential energy that can be released by freewheeling down the other side of the hill. Since the bicycle lost some of its energy to friction, it never regains all of its speed without additional pedaling. The energy is not destroyed; it has only been converted to another form by friction. Alternatively the cyclist could connect a dynamo to one of the wheels and generate some electrical energy on the descent. The bicycle would be traveling slower at the bottom of the hill than without the generator because some of the energy has been diverted into electrical energy

The energy from the generator will install supply into the battery

http://www.youtube.com/watch?v=2ZyJ5fZzgWw&feature=related

Piezoelectric energy harvesting

The piezoelectric effect converts mechanical strain into electric current or voltage. This strain can come from many different sources. Human motion, low-frequency seismic vibrations, and acoustic noise are everyday examples. Except in rare instances the piezoelectric effect operates in AC requiring time-varying inputs at mechanical resonance to be efficient.

Most piezoelectric electricity sources produce power on the order of milliwatts, too small for system application, but enough for hand-held devices such as some commercially available self-winding wristwatches. One proposal is that they are used for micro-scale devices, such as in a device harvesting micro-hydraulic energy. In this device, the flow of pressurized hydraulic fluid drives a reciprocating piston supported by three piezoelectric elements which convert the pressure fluctuations into an alternating current.

As piezo energy harvesting has been investigated only since the late 1990s, it remains an emerging technology. Nevertheless some interesting improvements were made with the self-powered electronic switch at INSA school of engineering, implemented by the spin-off Arveni. In 2006, the proof of concept of a battery-less wireless doorbell push button was created, and recently, a demonstrator showed that classical TV infra-red remote control can be powered by a piezo harvester. Other industrial applications appeared between 2000 and 2005, to harvest energy from vibration and supply sensors for example, or to harvest energy from shock.

Piezoelectric systems can convert motion from the human body into electrical power. DARPA has funded efforts to harness energy from leg and arm motion, shoe impacts, and blood pressure for low level power to implantable or wearable sensors. The nanobrushes of Dr. Zhong Lin Wang are another example of a piezoelectric energy harvester. They can be integrated into clothing. Careful design is needed to minimise user discomfort. These energy harvesting sources by association have an impact on the body. The Vibration Energy Scavenging Project is another project that is set up to try to scavenge electrical energy from environmental vibrations and movements. Xudong Wang's microbelt can be used to gather electricity from respiration. Finally, a millimeter-scale piezoelectric energy harvester has also already been created.

The use of piezoelectric materials to harvest power has already become popular. Piezoelectric materials have the ability to transform mechanical strain energy into electrical charge. Piezo elements are being embedded in walkways to recover the "people energy" of footsteps. They can also be embedded in shoes to recover "walking energy".

LTC3588-1 - Piezoelectric Energy Harvesting Power Supply

Features

·         950nA Input Quiescent Current (Output in Regulation – No Load)

·         450nA Input Quiescent Current in UVLO

·         2.7V to 20V Input Operating Range

·         Integrated Low-Loss Full-Wave Bridge Rectifier

·         Up to 100mA of Output Current

·         Selectable Output Voltages of 1.8V, 2.5V, 3.3V, 3.6V

·         High Efficiency Integrated Hysteretic Buck DC/DC

·         Input Protective Shunt – Up to 25mA Pull-Down at VIN ≥ 20V

·         Wide Input Undervoltage Lockout (UVLO) Range

·         Available in 10-Lead MSE and 3mm × 3mm DFN

·         Packages

Typical Application

Description

The LTC3588-1 integrates a low-loss full-wave bridge rectifier with a high efficiency buck converter to form a complete energy harvesting solution optimized for high output impedance energy sources such as piezoelectric transducers. An ultralow quiescent current undervoltage lockout (UVLO) mode with a wide hysteresis window allows charge to accumulate on an input capacitor until the buck converter can efficiently transfer a portion of the stored charge to the output. In regulation, the LTC3588-1 enters a sleep state in which both input and output quiescent currents are minimal. The buck converter turns on and off as needed to maintain regulation.

Four output voltages, 1.8V, 2.5V, 3.3V and 3.6V, are pin selectable with up to 100mA of continuous output current; however, the output capacitor may be sized to service a higher output current burst. An input protective shunt set at 20V enables greater energy storage for a given amount of input capacitance.

Applications

·         Piezoelectric Energy Harvesting

·         Electro-Mechanical Energy Harvesting

·         Wireless HVAC Sensors

·         Mobile Asset Tracking

·         Tire Pressure Sensors

·         Battery Replacement for Industrial Sensors

·         Remote Light Switches

·         Standalone Nanopower Buck Regulato

8051 microcontroller that use in this project

The Intel MCS-51 is a Harvard architecture, single chip microcontroller (µC) series which was developed by Intel in 1980 for use in embedded systems.^[1][2]Intel's original versions were popular in the 1980s and early 1990s. While Intel no longer manufactures the MCS-51, binary compatible derivatives remain popular today. In addition to these physical devices, several companies also offer MCS-51 derivatives as IP cores for use in FPGAs or ASICs designs.

Intel's original MCS-51 family was developed using NMOS technology, but later versions, identified by a letter C in their name (e.g., 80C51) used CMOStechnology and consumed less power than their NMOS predecessors. This made them more suitable for battery-powered devices.

 

Various 8051 microcontrollers

8051 microcontrollers use two different kinds of memory such as UV- EPROM, Flash and NV-RAM. Hence 8051 will not be seen in the part number even though it is the most popular member of the 8051 family.

        i.            8751 – This microcontroller is the UV-EPROM version of 8051. This chip has only 4K bytes of UV-EPROM. It is required to have access to the PROM burner and the UV-EPROM eraser to erase the contents inside the chip before it is programmed again. The disadvantage of using this memory is the waiting time of around 20 minutes to erase the contents in order to program it again. Due to this limitation, manufacturers fabricated flash and NV-RAM versions of 8051.

      ii.            AT89C51 from Atmel Corporation – Atmel fabricated the flash ROM version of 8051 which is popularly known as AT89C51 (‘C’ in the part number indicates CMOS). The flash memory can erase the contents within seconds which is best for fast growth. Therefore, 8751 is replaced by AT89C51 to eradicate the waiting time required to erase the contents and hence expedite the development time. To build up a microcontroller based system using AT89C51, it is essential to have ROM burner that supports flash memory. Note that in Flash memory, entire contents must be erased to program it again. The contents are erased by the ROM burner. Atmel is working on a newer version of AT89C51 that can be programmed using the serial COM port of IBM PC in order to get rid of the ROM burner.

             

Part Number	ROM	RAM	I/O pins	Timer	Interrupt	Vcc	Packaging
AT89C51	4K	128	32	2	6	5V	40
AT89C52	8K	256	32	3	8	5V	40
AT89C1051	1K	64	15	1	3	3V	20
AT89C2051	2K	128	32	3	8	3V	20
AT89LV51	4K	128	32	2	6	3V	40
AT89LV52	8K	128	32	3	8	3V	40

Table 1.2 – Versions of 8951 from Atmel (All ROM Flash)

There are different versions of packaging and various speed of the products mentioned in the above table.

Part Number	Speed	Pins	Packaging	Use
AT89C51-12PC	12MHz	40	DIP Plastic	Commercial
AT89C51-16PC	16MHz	40	DIP Plastic	Commercial
AT89C51-20PC	20MHz	40	DIP Plastic	Commercial

Table 1.3 – Various Speeds of 8051 from Atmel

Note: The part number AT89C51-16PC where AT – Atmel, C - CMOS (consumes less power), 12 - Speed as 12 MHz, P – Plastic DIP packaging, C - Commercial use. AT89C51-12PC is favourably used by students for their projects.

iii.   DS5000 from Dallas Semiconductor – Dallas Semiconductor fabricated the NV-RAM version of the 8051 which is known as DS5000. The PC serial port is utilized to load the program onto the in-built ROM. The advantage of NV-RAM memory is the facility to erase the contents one byte at a time.

      v.             

Part Number	RAM	ROM	Timers	I/O pins	Interrupts	Vcc	Packaging
DS5000-8	128	8K	2	32	6	5V	40
DS5000-32	128	32K	2	32	6	5V	40
DS5000T-8	128	8K	2	32	6	5V	40
DS5000T-8	128	32K	2	32	6	5V	40

Table 1.4 – Versions of 8051 from Dallas Semiconductor

Note: ‘T’ signifies the real time clock (RTC) which is different from the timer. Even though the power is turned off, the real – time clock generates and displays the date and the time of day.

The variety range of speed and packaging versions of DS5000 which is shown in the Table 1.5

Part Number	NV-RAM	Speed
DS5000-8-8	8K	8MHz
DS5000-8-12	8K	12MHz
DS5000-32-8	32K	8MHz
DS5000-32-12	32K	12MHz
DS5000T-8-12	8K	12MHz
DS5000T-32-8	32K	8MHz

Table 1.5 – Versions of 8051 Dallas Semiconductor

Note: The part number DS5000-8-8 where 8 - 8K NV-RAM, 8 – Speed of 8MHz. DS5000-8-12 is favourably used by students for their projects.

iv.    One - Time - Programmable (OTP) versions of the 8051 – This version of microcontroller is cheaper and available from various manufacturers. The manufacturers use OTP microcontroller for mass production because the price per unit is very cheap