Eco-electric energy generator system using human exercise activities

Today human need for electrical energy is very high. For that we need to find an alternative power plant renewable energy, especially environmentally friendly. One type of an environmenttally friendly power plant is a generator which is harnessing human-generated energy when exercising by using a static bike. This equipment is used on average 6 hours per day at 5.00-8.00 hours and 17:00 to 20:00 hours. In this research, a power plant system by utilizing human motion exercising from wheel rotary mechanics, generators, BCU (Battery Control Unit), and battery will be designed. The rider can see from the LCD when the battery condition is full, the battery is charge, the battery does not get energy from the generator, inverter on, inverter off, battery voltage and generator voltage. At the testing stage, 14 participants cycling for 15 minutes produced electrical energy on average of 594 Joules, with an age range of 20-23 years old. The resulting energy can turn on the light 3 Watt between 160 -251 seconds or 198 seconds on average. When accumulated 14 cycled samples with 15 minutes each (total 210 minutes) can generate 8313 Joule electric energy and can turn on 3 Watt lamp for 46 minutes 11 seconds.


Introduction
The human need for electrical energy today is very high. Most of this need is supplied by power plants using fossil fuel that is not environmentally friendly. According to various data such as the United Nations Framework Convention on Climate Change (UNFCCC) in Bali presents the needs of developing countries to get the transfer of environmentally friendly technologies for contributing to the success of reducing emissions and preventing global warming. One form of eco-friendly power plant is harnessing human-generated energy when exercise using static bicycle [1], [2].
This system is used for 6 hours average per day at 5.00 to 8.00 am and 05:00 to 08:00 pm. The average cycling activities generates 75 watts / hour, or 450 watts in 6 hours [1]- [4]. In this research, a system that include of mechanical wheel rotation, DC generator, BCU (Battery Control Unit), and battery has been designed. This system is also equipped with LCD, so that users can know the condition of full battery, batteries are being filled, batteries do not get energy from the generator, inverter condition on / off, battery voltage and output voltage generator. The eco-electric energy generator was implemented using system configuration show on Fig.1. The specifications of the each part, respectively:  Chain is the link between the stroke and the rear wheel, and drive belt is the link between the rear wheel and the DC motor.  Generator produces voltages between 10 volts to 60 volts.  Rotary encoder and optocopler sensor to show the ADC and rotational speed.  Battery control unit as a safety and limit voltage into the battery.  Battery for power storage generated by 35Ah 12 volt and 60Ah 12Volt.  Minimum system to control and adjust speed, voltage, ADC.  AC and DC lamps as loads used.  LCD to display the voltage, speed, power obtained.

System details
One form of eco-friendly power plant is to utilize the energy produced by humans when exercise using a static bike. When bicycle is pedalled, the wheels will rotate and generate DC electric voltage in the coil according to the law of electric motion force and will output current if loaded.

Chain mounting
The chain function is as a player that moves power from the pedal to the wheel then move the tire. The position of the pedal chain is on the right and the position of the motor chain is on the left of the rider. The design of the chain is as follows: With value of radius of holder of chains equal to: R1: r = 10 cm; R2: r = 5.5 cm; R3: r = 1.8 cm

Battery control unit
Battery control unit serves for the safety and limit the voltage that goes into the battery. The circuit schematic for the BCU showed on Fig.4.

Display circuit
To display some variables need to be monitored by the user the system used LCD display connected to the minimum circuit microcontroller. This circuit uses ATMEGA8535 made by ATMEL with configuration as shown in figure 4.   Fig. 5. LCD circuit connected to ATMEGA8535 minimum system.

Measurement of battery voltage
Measurement of battery voltage before being given a load of 12.22V and if given the load voltage to 11.66V.
Measured battery acid condition using Hydrometer, Normal batteries have a specific gravity of 1.27 -1.29kg / cm3. If below it then must be in charge replaced or replaced with new battery acid.    The calculated energy used by 14 participants when cycling over static bike for 15 minutes are shown on Fig.9. As we can see the weight of each participants denote the energy generated.