The document discusses a presentation on wireless charging pads. It describes how wireless charging works using electromagnetic induction to transfer energy between two coils. The key components are a transmitting coil connected to a power source which generates an alternating electromagnetic field, and a receiving coil connected to the device being charged. When both coils are in close proximity and resonating at the same frequency, energy is wirelessly transferred from the transmitting coil to the receiving coil to charge the device. Applications include charging portable electronics more conveniently without wires.

1. A
synopsis presentation
on
WIRELESS CHARGING PAD
Submitted by –
Sachin Malik

2. What is wireless charging pad?
• Uses an electromagnetic field to transfer
energy between 2 objects through
eletromagnetic induction.
• Energy is sent through an “Inductive
Coupling”

3. Principle of Operation
• Wireless charging is based on the principle of
magnetic resonance or Inductive Power
Transfer(IPT).
• This is a process of tranferring an electrical
current between two objects through the use
of coils to induce an electromagnetic field.

5. Block Diagram
DC POWER
Inverter with
high frequency
Transmitter
coil
Air as core
Transmitting Section
Reciever coil Rectifier
Receiving section
Charging
control unit Battery

6. Resonant wireless charging
• IPT uses resonance in order to achieve
coupling of the transmitter and receiver coil
and it is achieved when both the coils oscillate
or “resonate” at same frequency.
• This resonant frequency refers to the
frequency at which an object naturally
vibrates or rings.

7. Literature survey
• The wireless era was started by two European scientists, James Clerk
Maxwell and Heinrich Rudolf Hertz. In 1984, Maxwell presented the
Maxwell’s equations by combining the works of Lorentz, Faraday, Ampere
and Gauss .
• He predicted the propagation of electromagnet waves in free space at the
speed of light. His theory was accepted 20 years later, after Hertz validated
electromagnetic wave (wireless) propagation. Hertz demonstrated RF
generation, propagation and reception in the laboratory.
• Marconi started to commercialized the use of electromagnet wave
propagation for wireless telegraphs and allowed the transfer of information
from one continent to another without physical connection .
• Since the cellular mobile phone system was introduced in the early 1980’s,
the wireless industry has gone several generations of revolutionary changes.
• Motorola Mobility launched their Droid 3 and Droid 4, both optionally
support the Qi standard.

8. Motivation
• The motivation of choosing “wireless charging pad”
as a project was the purpose of knowing the fact that
how without using wires we can make a charger.
• This project’s main objective was to enhance my
knowledge and to construct a wireless charging pad
for a mobile.

9. Advantages
• Greater spatial freedom
• Charging multiple devices simultaneously
• It has minor effect of obstacles.

10. SKIN EFFECT
• It is the tendency of an AC to become
distributed within a conductor.
• The current density is largest near the surface
of the conductor and decreases with greater
depths in the conductor.
• The electric current flows mainly at the “skin”
of the conductor between the outer surface
and a level called Skin depth.
• At 60Hz in copper, the skin depth is about
8.5mm.

11. How to overcome Skin Effect?
• Reducing the size of the coils from thick to
thin.
• Using ‘n’ number of thin coils.

12. Advantages of wireless charging pad
• Protected connections
• Low infection risk
• Durability
• Increased convenience

13. Disadvantages of wireless charging
pad
• Inefficient
• More expensive
• Inconvenient

14. Applications
• Portable electronic devices
• Transportation
• Dual standard

15. References
• "Rulemaking: 2001-06-26 Updated and
Informative Digest ZEV Infrastructure and
Standardization" . title 13, California Code of
Regulations. California Air Resources Board. 2002-
05-13. Retrieved 2010-05-23. Standardization of
Charging Systems.
• “London charges ahead with wireless electric
vehicle technology”. Source London, Transport for
London. 10 November 2011. Retrieved 2011-11-11