Friday, August 9, 2013
Mobile Phone and iPod Battery Charger
Charge your iPod without connecting it to a computer!
Using the USB port on your computer to charge your player’s batteries is not always practical. What if you do not have a computer available at the time or if you do not want to power up a computer just for charging? Or what if you are traveling? Chargers for Mobile Phones iPods and MP3 players are available but they are expensive and you need separate models for charging at home and in the car.
This charger can be used virtually anywhere. While we call the unit a charger, it really is nothing more than a 5V supply that has a USB outlet. The actual charging circuit is incorporated within the iPOD or MP3 player itself, which only requires a 5V supply. As well as charging, this supply can run USB-powered accessories such as reading lights, fans and chargers, particularly for mobile phones.
The supply is housed in a small plastic case with a DC input socket at one end and a USB type "A" outlet at the other end, for connecting to Mobile Phone, an iPod or MP3 player when charging. A LED shows when power is available at the USB socket. Maximum current output is 660mA, more than adequate to run any USB-powered accessory.
Pictures, PCB and Circuit Diagram:
Front View Of Mobile Phone and iPod Battery Charger Circuit
Bottom View Of Mobile Phone and iPod Battery Charger Circuit
PCB Layout Of Mobile Phone and iPod Battery Charger Circuit
Mobile Phone and iPod Battery Charger Circuit Diagram
| Parts | Description |
| P1 | 1K |
| R1 | 1R-0.5W |
| R2 | 1R-0.5W |
| R3 | 1R-0.5W |
| R4 | 1K |
| R5 | 560R |
| R6 | 10R-0.5W |
| R7 | 470R |
| C1 | 470uF-25V |
| C2 | 100nF-63V |
| C3 | 470pF |
| C4 | 100uF-25V |
| D1 | 1N5404 |
| D2 | 1N4001 |
| D3 | 1N5819 |
| D4 | 5.1V-1W Zener Diode |
| D5 | 5mm. Red LED |
| L1 | 220uH |
| S1 | USB A Type Socket |
| SW1 | On/Off Switch |
| IC1 | MC34063A |
Specifications:
Output voltage ----------------------5V
Output current ---------------------660mA maximum for 5V out
Input voltage range ------------------9.5V to 15V DC
Input current requirement ----------500mA for 9V in, 350mA for >12V input
Input current with output shorted--- 120mA at 9V in, 80mA at 15V in
Output ripple ------------------------14mV (from no load to 660mA)
Load regulation ----------------------25mV (from no load to 660mA)
Line regulation ----------------------20mV change at full load from 9 to 18V input
No load input current ----------------20mA
(The specification for the computer USB 2.0 port requires the USB port to deliver up to 500mA at an output voltage between 5.25V and 4.375V).
The circuit is based around an MC34063 switch mode regulator. This has high efficiency so that there is very little heat produced inside the box, even when delivering its maximum output current. The circuit is more complicated than if we used a 7805 3-terminal regulator but since the input voltage could be 15V DC or more, the voltage dissipation in such a regulator could be 5W or more at 500mA. and 5W is far too much for a 7805, even with quite a large heatsink. Credit for this circuit goes to SiliconChip, A wonderful electronics magazine.
Source :www.extremecircuits.net
Wednesday, April 10, 2013
LM4651 and LM4652 170W power amplifier
Part of this power amplifier driver using the LM4651 IC designed specifically for the purpose of the class AB amplifier driver with short circuit protection feature, containing under voltage, thermal shutdown protection and standby functions. Section 170 Watt power amplifier using LM4651 IC with a MOSFET power amplifier is equipped with temperature sensors that will be used by IC LM4651 as controlnya thermal signal. IC IC LM4651 and LM4652 are designed specifically to each other in pairs to create a class AB power amplifier with protection features are detailed. Detailed series of 170 Watt power amplifier can be seen in thethe following figure .
Power amplifier circuit requires supply voltages +22 V DC symmetrical 0-22V. Power Amplifier with IC LM4651 and LM4652 are often used in portable HiFi systems such as powered speakers, power subwoofer and car audio power Booter. D1, D2, D3 and D4 in series 170 watt power amplifier with LM4651 and LM4652 is a 22V zener diode.
Wednesday, April 3, 2013
Evolving Technology and Auto Sound Systems
Friday, March 29, 2013
How to Understand and Use Transistors in Circuits
semiconductor devices found today. If there wouldn’t be transistors
there wouldn’t be any ICs or any other semiconductor component. Even ICs
are made up of millions of closely knit transistors which constitute
the features of the particular chip.
electronic hobbyists usually find it difficult to handle these useful
components and configure them as circuits for an intended application.
transistors are generally a three lead active electronic component
which fundamentally works as a switch for either switching ON or
switching OFF power to an external load or the following electronic
stage of the circuit.
are normally recognized by their external package in which the
particular device may be embedded. The most common types of package in
which these useful devices are enclosed, are the T0-92, TO-126, TO-220
and TO-3. We will try to understand all these specifications of
transistors and also learn how to use them in practical circuits.
like BC547, BC557, BC546, BC548, BC549, etc all come under this
category. These are the most elementary in the group and are used for
applications involving low voltages and currents. Interestingly this
category of transistors is used most extensively and universally in
electronic circuits due to their versatile parameters.
base voltage is not more than 6, but they can be easily triggered with a
voltage level as low as 0.6 volts at their base. However the current
must be limited to 3 mA approximately.
the printed side toward us, the right side lead is the emitter, the
center one is the base and the left hand side leg is the collector of
the device.
are mainly of two types, an NPN type and a PNP type, both are
complementary to each other. Basically they both behave the same way but
in the opposite references and directions.
example an NPN device will require a positive trigger with respect to
the ground while a PNP device will require a negative trigger with
reference to a positive supply line for implementing the specified
results.
three leads of the transistor explained above needs to be assigned with
specified inputs and outputs for making it work for a particular
application which obviously is for switching a parameter.
emitter of any transistor is the reference pin out of the device,
meaning it needs to be assigned the specified common supply reference so
that the remaining two leads can operate with reference to it.
NPN transistor will always need a negative supply to be connected at
its emitter lead for functioning while for a PNP, a positive supply
line. The collector is the load carrying lead of a transistor and the
load which needs to be switched is introduced at the collector of a
transistor (see figure).
base of a transistor is the trigger terminal which is required to be
applied with a small voltage level so the current through the load can
pass through, across to the emitter line making the circuit complete and
operating the load.
removal of the trigger supply to the base immediately switches OFF the
load or simply the current across the collector and the emitter
terminals.
are medium type of power transistors used for applications which
require switching of powerful relatively powerful loads lie
transformers, lamps etc. and for driving TO-3 devices, typical egs are
BD139, BD140, BD135 etc.
the device with its printed surface facing you, the right side lead is
the emitter, the center lead is the collector and the left side lead is
the base.
base trigger can be anywhere from 1 to 5 volts with currents not
exceeding 50 mA depending upon the power of the loads to be switched.
can be seen in metallic packages as shown in the figure. The common
examples of TO-3 power transistors are 2N3055, AD149, BU205, etc.
the lead side of the device toward you such that the metal part beside
the leads having larger area is held upward (see figure), the right side
lead is the base, the left side lead is the emitter while the metallic
body of the device forms the collector of the package.
function and operating principle is just about the same as explained
for the small signal transistor however the power specs increase
proportionately as given below:
trigger should be optimally around 5 volts, with current levels from 10
to 50 mA depending upon the magnitude of the load to be triggered. The
base triggering current is directly proportional to the load current.