In this beautiful experiment we Transmit Electricity without wires. For this we need to make a small circuit. This project was made by several student of the New English School, Pune, India. This historic school was set up by Lokmanya Tilak in 1880. The power supply is a Nokia Mobile charger and it is connected to 220-volt AC. This input goes through an electronic circuit. Instead of a PCB we have assembled the circuit on a transparent sheet of plastic. The circuit consists of a transistor, three capacitors and a resistance. This red one is a 1-nf capacitor. The Green one is a 4.7-ng capacitor. The resistance is 5.6K and the transistor used is DD139. The Yellow one is a 100-nf capacitor. The green coils are actually two coils with 5 turns each. So, one coil will have 10 turns and the other will have 5 turns. There is a live wire and a neutral wire. This circuit basically converts the charger DC current into AC. This AC current produces a magnetic field in the green coil.
I am Ratnakar. My friend Nachiket gave you information about the primary coil. I will tell you about the secondary coils. This green coil converts the DC from the Nokia charger into AC. This is a secondary coil made from 5 turns of insulated copper wire. A 15-nf capacitor is attached to coil. The Yellow LED is also attached parallel to the capacitor. When we bring the 5 turn secondary coil near the green primary coil current is induced in the secondary coil – the capacitance gets charged and the yellow LED glows.
The second secondary coil has 10 turns of insulated copper wire and 4 small capacitors attached in parallel. This increases the strength of the coil and the Red LED lights much more brightly. You can lift this coil up for a considerable distance and the LED will still light.
The third secondary coil has 20 turns of insulated copper wire and 3 small capacitors attached in parallel. One capacitor is 30-nf and the other two are 20-nf each. There is also a LED attached. This increases the strength of the coil further. You can lift this coil up and electricity transmission will still take place.
The fourth secondary coil has 25 turns of insulated copper wire and NO capacitors at all. There are three LEDs. Despite no capacitors WIRELESS electricity is still transmitted to the coil and all the three LEDs light up. Because there are no capacitors the capacity of this coil is limited. All secondary coils can be placed together and the LEDs light up. But on removing the intermediate coil the coil which is far away turns OFF.
I am Tejas. Because of the spinning magnetic field in the green coil some current is induced in the secondary coil and that charge sets stored in the capacitance. And it is this charged capacitor which lights up the LEDs. If I place a strong magnet inside the green primary coil – this permanent magnet will absorb the magnetic lines of forces and there will be on induced current in the secondary coils. Thus the LED will turn OFF. This work was supported by IUCAA and Tata Trust. This film was made by Ashok Rupner TATA Trust: Education is one of the key focus areas for Tata Trusts, aiming towards enabling access of quality education to the underprivileged population in India. To facilitate quality in teaching and learning of Science education through workshops, capacity building and resource creation, Tata Trusts have been supporting Muktangan Vigyan Shodhika (MVS), IUCAA’s Children’s Science Centre, since inception. To know more about other initiatives of Tata Trusts, please visit