Introduction: Human Powered Sewing Machine for Clean Electric Power Generation

By SUNIL KUMAR THAKUR
About: Awarded with Excellence in Innovation and Research Award from Veltech University

An innovative method of power generation. With the advent in the field of research to discover new renewable sources of energy it was found that if we exploit the increasing population, human muscle power could also be used as a resource of electric power. This motivated to modify a system that could trap the mechanical energy of human while sewing. Sewing machines are easily available and robust and it requires human power.

The main objective behind this present work is to provide energy to communities without electricity supply or people deprived of electricity for the basic needs like electrical power for small electronic devices like charging a cell phone ,or to run a portable radio, glowing LED lamps during night or when needed or running other small appliances [1] . Normally sewing machines without any electric supply is used in the country side. Hence the idea conceived is to generate DC with the rotation of the rotating ridged knob when it comes in contact with the belt of the machine.

Step 1: ​INTRODUCTION

India is the second most populous country in the world. Like many other countries where agriculture is the main activity, biomass and other non – commercial fuels constitute around 40% of energy requirements in India. Around 85.49% of Indian villages are electrified [3]. Human powered generators have been of interest at many places where no other alternative electricity generator has been viable. While using pedal power is not a new concept in itself, it has not been successfully used on a wider scale [2]. If we can generate some amount of energy from the spinning wheel of the sewing machine, while stitching by attaching a cycle dynamo to the wheels we can convert the mechanical to electrical energy(though this may be only a few volts or even lesser).

Step 2: THE SEWING MACHINE

A sewing machine is a machine used to stitch fabrics, cloths Sewing machines were invented during the first Industrial revolution to decrease the amount of manual sewing work performed in clothing companies. Since the invention of the first working sewing machine, generally considered to have been the work of Englishman Thomas Saint in 1790. The sewing machine has greatly improved the efficiency and productivity of the clothing and allied industries.

Home sewing machines are designed for one person to sew individual items while using a single stitch type. In a modern sewing machine the fabric easily glides in and out of the machine without the inconvenience of needles and thimbles and other such tools used in hand sewing, automating the process of stitching and saving time.

Step 3: THE POWER GENERATOR

The power generator in its simplest form as shown in Fig, is nothing but a bicycle generator, where a small dc generator is attached to one of the wheel (generally back wheel) of the bicycle. The bicycle generator is relatively small and a small torque is required to make rotation of its rotor. Dynamos operate by converting rotational kinetic energy to electrical energy using a magnet and solenoid. It takes mechanical power from the wheel of the rotating machine, which create a powerful magnetic field, and a rotating magnet (called rotor) which distorts and cuts through the magnetic lines of flux coming from the stator. The permanent magnet will rotate inside the solenoid at an angular velocity, ω as shown in fig. When the rotor cuts through lines of magnetic flux it produces electricity.

Faraday’s law states that the emf produced by a dynamo is related to the rate of change of the magnetic flux (flux linkage) in the solenoid. The magnetic flux, Φm, in the solenoid whose radius is r and with number of turns N [6] is shown in fig.

Where B is the magnetic field strength of the permanent magnet and t is the time. By using Faraday’s law, it can be shown that the peak emf output Vm for the magnet.

Step 4: EXPERIMENTAL SET UP

The block diagram representation of the complete experimental set up is shown in Fig.3 and the actual experimental set up is depicted in Fig.4 The battery get charged via the charge controller . A charge controller limits the rate at which electric current is added to or drawn from electric batteries. It prevents overcharging and may protect against overvoltage, which can reduce battery performance or lifespan, and may pose a safety risk. It may also prevent completely draining (deep discharging) a battery, or perform controlled discharges, depending on the battery technology, to protect battery life.

Step 5: PROCESSING CIRCUIT & POWER STORAGE

The processing circuit Fig. consists of a diode bridge rectifier and a filter capacitor to lead the AC output to become a DC and later to be stored in a battery.

A bridge rectifier is an arrangement of four or more diodes in a bridge circuit configuration which provides the same output polarity for either input polarity. It is used for converting an alternating current (AC) input into a direct current (DC) output as per the equation (1).

The LM317 has three pins: input, output, and adjustment (as shown terminal 1, 2 & 3). The device is conceptually an op amp with a relatively high output current capacity. The inverting input of the amp is the adjustment pin, while the non-inverting input is set by an internal band gap voltage reference which produces a stable reference voltage of 1.25 V. The output is as per the equation here V is the Vdc.

Hence DC rectified voltage and output of LM317 will be linear, Hence Dynamo speed Vs output will be linear as viewed from equation 1 & 2. The battery chosen is a 12 V 7.2 Ah battery. Having Output Power Wattage: 86.4 W Input Voltage: 12 V Output Voltage: 14.4 V, An LED bar level indicator with color coded LEDs is used to indicate level of charge of battery. A center zero ammeter (-8A-0-+8A) is used to display charging rate.

Step 6: ANALYSIS



• The sewing machines normally do not made to operate at a constant speed. In spite of the intermittent speed which happens in practice but For experimental analysis the machine was made to run at a speed(optimum ) and the corresponding voltage outputs were measured. When the rotation was around 1000 rpm at that time the output was nearing 7.18V. And most of the times it rotates at 1000 rpm.
• The average power produced by the dynamo can be sufficient to charge a mobile phone.
• The power needed to charge a mobile phone can be up to approximately 15 W [7]. However, the dynamo produces alternating current (ac), whereas the mobile phone will need to be charged using a direct current (dc) source [3]
• Another analysis was made to ensure that battery chosen must retain the charge for a longer duration. And the battery must retain the charge for a longer duration even though the machine is not operated for several days.
• Fig is Speed Vs voltage output
• Fig. shows the voltage output in rectified form Vs the speed. The output of dynamo will be as per The equation In spite of the intermittent speed of the .machine the battery will be able to retain the charge and fulfill the requirements.


Step 7: CONCLUSION

The usage of this innovative experimental work will be for rural or tribal areas or islands remotely located areas. The major application will be for battery charging and lighting and for that USB charging port is provided .Any person with normal health condition will be able to run a sewing machine. The machine does not require any major modifications.