2. EARPHONE JACK
Usually 2.5 and 3.5mm jacks have been used in smart phones
and cell phones.
While, stereo and home theatre like
equipment generally have 6.3mm sockets.
In time, the common headphone
jack on smart phones is expected to become
history, replaced by wireless (Bluetooth).
3. Cont….
In 2016, Apple eliminated the headphone jack on the
iPhone 7.
Older phones used a smaller 2.5mm jack
for phone headsets.
The 2.5 and 3.5 mm jacks are used with mobile devices,
while the 6.3 mm connectors (bottom) are typically found
on non-portable equipment.
3.5=diameter
of the
connector
4. SIZE OF SOCKET
• 2.5 mm mono (TS)
• 3.5 mm mono (TS)
• 3.5 mm stereo (TRS)
• 6.35 mm ( 1⁄4 in) (TRS)
5. JACK
Jack : Part of the earphone which takes electrical signals from
the audio output port of the devices like mobile phones,
laptop, computers, music player etc.
There are three contact areas known
as the TIP, RING and the SLEEVE as shown
in the image and therefore this connector is
also called as TRS connector.
6. CONSTRUCTION
A phone connector, also known as phone jack, audio jack, headphone
jack or jack plug, is a family of electrical connector typically used
for analog signals.
The phone connector was invented for use in telephone switchboards in
the 19th century and is still widely used.
It is cylindrical in shape, with a grooved tip to retain it. In its original
audio configuration.
It typically has two, three, four and, occasionally, five contacts. Three-
contact versions are known as TRS connectors, where T stands
for "tip", R stands for "ring" and S stands for "sleeve".
Ring contacts are typically the same diameter as the sleeve, the long
shank. Similarly, two-, four- and five- contact versions are called TS, TRRS
and TRRRS connectors respectively.
The outside diameter of the "sleeve" conductor is 1⁄4 inch (6.35
millimeters). The "mini" connector has a diameter of 3.5 mm (0.14 in)
and the "sub-mini" connector has a diameter of 2.5 mm (0.098 in).
7. COMPLETE CIRCUIT
At the most basic level, an earphone is a loop of wire with
current running through it.
This electric current in the loop then interacts with a
permanent magnet which in turn pushes the air—that's
sound.
8. TRS AUDIO JACK
TRS audio plugs are found on standard stereo headphones that
don’t have a microphone. After you cut into the cable, you’ll
probably find one of three common ways these can be wired:
Copper wire ground sheath wrapped around two insulated
audio signal wires.
Two separate insulated wires, each with its own signal wire
and a ground wire inside.
Separate insulated wires for the ground, right audio, and left
audio inside a single cable.
Usually red wires are the right audio channel and blue wires
are the left audio channel.
11. TRRS AUDIO PLUG
The TRRS audio plug is found on iPhone headphones and
other headphones that have a microphone. After you cut
open the plastic insulating sheath you’ll find 5 separate
wires:
Solid red wire: right audio channel signal
Red and copper twisted wire: ground for the right audio
channel
Solid green wire: left audio channel signal
Green and copper twisted wire: ground for the left audio
channel
Red and green sheath with a copper wire inside: Inner
copper wire is the microphone signal, outer sheath is the
microphone ground.
14. TRANSFERING THE MESSAGE
Encodes the message [ ASCII or morse code].
Convert encoded message into audio signal.
Send the audio signal.
Receives audio signal.
Interrupts [filter] audio signal.
Decodes digital signal into original message.
15. SAMPLING FREQUENCY
The total number of time the signal is sampled in one second
is called as sampling frequency.
Only 44.100hz is guaranteed on all android devices.