Showing posts with label phone. Show all posts
Showing posts with label phone. Show all posts

Monday, December 16, 2013

cell phone jammer is necessary to the large scale examination

cell phone jammer is necessary to the large scale examination.
In fact, not a capacitive screen stylus is not supported, but to achieve this function by the binding of IC to rely on the decision, and the capacitance of the current screen handwriting support its production process is very complicated, of course, yield is not high. Of course, in addition to IC technology constraints, there are some functions limited by patents so now you want to use the stylus to achieve capacitive screen is still difficult. Resistive screen with capacitive screen and the usual articles in the TFT screen, AMOLED screen, what is the relationship? In fact, TFT screen, AMOLED display screen is a kind of resistance with capacitive screen and touch-screen display such essentially different in their light-emitting display can. Behind the integrated backlit TFT screen displays bright, while switching so much energy, but the latest AMOLED screen, light-emitting diodes with self-luminous features, so not only can the same effect with colorful reality, but also significant savings in energy consumption. The capacitive screen and the screen is a resistive touch screen located in the front, but can not operate like a TFT touch screen, AMOLED screen as light. cell phone jammer intelligent system is produced based on the deep analysis of the communication mechanism.
In fact, a simple resistive screen can also be achieved multi-touch, but we have introduced the above works, so the two points after exposure to the screen may result in A, B are two points can not touch insensitivity caused by a balanced force measurement the phenomenon. Is single-touch devices can only identify a local contact point is more like the IPHONE two hands or more, as can also be identified, such as you do with two fingers to enlarge map installed on the front enlarged. Will identify a single point of responsibility into the middle of two points. It is the connection description of cell phone jammer intelligent system.
The so-called thin-film field-effect transistor, liquid crystal display is the LCD pixels are each integrated in the subsequent thin-film transistor to drive. Which can be high speed, high brightness, high contrast display screen information.
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Tuesday, October 1, 2013

Mobile Phone Battery Charger Circuit Diagram

Small and portable unit, Can be assembled on veroboard

Mobile phone chargers available in the market are quite expensive. The circuit presented here comes as a low-cost alternative to charge mobile telephones/battery packs with a rating of 7.2 volts, such as Nokia 6110/6150.

Circuit diagram:

Mobile_Phone_Battery_Charger_Circuit diagram Mobile Phone Battery Charger Circuit Diagram

Parts Description
R1 1K
R2 47R
R3 10R
R4 47R
C1 1000uF-25V
D1 LEDs any color
D2 LEDs any color
D3 LEDs any color
D4 1N4007
D5 1N4007
Ic1 LM7806
T1 9VAC Xformer 250mA
BR1 Diode bridge 1A
 

Circuit Operation:

The 220-240V AC mains supply is down-converted to 9V AC by transformer T1. The transformer output is rectified by BR1 and the positive DC supply is directly connected to the charger’s output contact, while the negative terminal is connected through current limiting resistor R2. D2 works as a power indicator with R1 serving as the current limiter and D3 indicates the charging status. During the charging period, about 3 volts drop occurs across R2, which turns on D3 through R3.

An external DC supply source (for instance, from a vehicle battery) can also be used to energies the charger, where R4, after polarity protection diode D5, limits the input current to a safe value. The 3-terminal positive voltage regulator LM7806 (IC1) provides a constant voltage output of 7.8V DC since D1 connected between the common terminal (pin 2) and ground rail of IC1 raises the output voltage to 7.8V DC. D1 also serves as a power indicator for the external DC supply. After constructing the circuit on a veroboard, enclose it in a suitable cabinet. A small heat sink is recommended for IC1.

Source :www.extremecircuits.net

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Monday, April 8, 2013

Car Mobile Phone Charger Circuit

Car Mobile Phone Charger Circuit
Cellphone battery charging process when were done traveling is a big problem. Because when traveling source of power supply is generally difficult to find. If you turn on your phone then the battery continuously over time will run out within a period of five to six hours and eventually mobile phones unusable. Here is described a series of simple charger that will increase battery life two to three hours.


In principle, the charger uses a series of Limited Voltage Current Source. Generally requires cellphone battery voltage 3.6 - 6 volts DC and currents 180-200 mA to perform the charging process. Cellphone battery usually consists of three NiCd battery cells, and each cell has a voltage of 1.2 volts potential. At the speed - average low flows required to charge mobile phone battery about - about 100mA.

Car Mobile Phone Charger Circuit schematics

In this series there is a 12V voltage source consists of 8 regular battery cells (each cell 1.5 Volt) able to supply current at 1.8 A which is connected with output terminals.

The circuit is also able to monitor the battery voltage level which is in charge. And will automatically cut off the charging process when the output terminal detects a certain battery voltage level predetermined. Timer IC NE555 is used to charge and monitor the voltage level in the battery, Pin 5 (IC1) as the control voltage using a reference voltage zener voltage 5.6Volt. Voltage at Pin 6 as the threshold set by VR1 and the voltage at Pin 2 as the trigger is set by VR2.

When the cellphone battery is connected in series (the Charging Process) applied voltage on PIN2 (IC1) as a trigger would be below the value 1 / 3 Vcc and will cause the Flip-Flop in IC1 will ON and on Pin 3 (IC1) will be high (Cause transistor T1 saturation.). When the battery is full (Full Charge) then the voltage will rise and the voltage on the PIN2 (IC1) will be above the level of trigger point threshold. This will cause the Flip Flop OFF and the output will be low (transistor T1 causes the cutoff) and indirectly also the charging process will stop.

Pin 6 (Threshold IC1) is set at 2 / 3 Vcc by using VR1, transistors T1 which is used to increase the charging current. R3 value is very important to provide the charging current, by setting the value of R3 to 39 ohms then the charging current supplied approximately 180mA. This circuit can be built on any type of PCB (General Purpose PCB) for the calibration process using the DC voltage level cutoff Variable Power Supply. Connect the output terminal circuit with Variable DC Power Supply and set on 7 volts. Adjust VR1 in middle position and slowly adjust VR2 until LED1 OFF, this indicates Low Output. LED1 should turn on when the DC Variable Power Supply voltage is reduced below 5V. LED1 Status flame shown in the table below. Closed circuit with plastic casing and use a suitable connector for connecting to the Battery for Mobile.
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