Friday, January 10, 2014

cell phone jammer can be turned off point to point

 cell phone jammer can be turned off point to point.
When booking air tickets, travelers need to provide their own mobile phone number and e-mail address, Air France will be by telephone within 14 days before the plane took off, the form of text messages or e-mail to notify passengers of flight changes, such as: delay, cancel or change the gate . In addition, after taking off, if the checked baggage does not arrive in time, they will use SMS to inform passengers. Pocket social network marketing the new hot spot in the aviation industry. According to the end of 2009, Morgan Stanley, "Mobile Internet Research Report, the global social networking site has 830 million unique users, an increase of 20%. Social networking sites have become a common practice in the global, showing the pack around and starting the trend, the specific distribution is as follows. It is the centralized power switch of cell phone jammer .It might greatly affect and influence the shielding radius and range of cell phone jammer.In general, this kind of advertising eventually implement a purpose, to promote the occurrence of trading behavior, the vast majority of all text message based, This requires that mobile advertising can bring value to the target customers, and inspire their direct response. After all, compared with other media, running on the phone certainly is not the same. Compared to the proliferation of spam, direct advertising to focus on the value of information is brought to the recipient. After all, the arrival rate does not equal acceptance rate, the response rate is critical. In other words, the customer receives information included because the information prompted the incentive of the recipients of action, they are often able to be touched, the occurrence of a response. Therefore, mobile advertising, content is not the mass, but rather fine; release is not that extensive, but rather the response. The cell phone jammer system is energy-saving.As the "core" of the "leader", the mobile application development engineers and other R & D personnel, the new development for the Chinese Internet to create endless possibilities. Secret four pay levels. The mobile phone application development engineers generally monthly salary of 5,000 to 10,000 yuan. Different regions, slightly different, but generally it seems, mobile application development engineers is a lucrative career in the industry, which is self-evident. Beijing, Shanghai, Shenzhen, mobile application development engineer salary is generally 8,000 to 10,000 yuan, and other parts of the slightly lower, but generally can reach 5000 ~ 8000 yuan. 3G DreamWorks undertaken by the four-dimensional creative education, science and technology Co., Ltd., the company also has a well-known animation and game education brand 4D DreamWorks. To turn cell phone jammer on or off periodically.
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Build a 3V Battery To 5V Dc Dc Converter Circuits Diagram

Build a 3V Battery To 5V Dc/Dc Converter Circuits Diagram. A common power-supply requirement involves converting a 2.4- or 3-V battery voltage to a 5-V logic supply. This circuit converts 3 V to 5 V at 40 mA with 85% efficiency. When Ic (pin 6) is driven low, the output voltage will be the battery voltage minus the drop across diode Dl. 

The optional circuitry that uses CI, R3, and R4 lowers the oscillator frequency when the battery voltage falls to 2.0 V. This lower frequency maintains the output-power capability of the circuit by increasing the peak inductor current, which compensates for the reduced battery voltage.

3V Battery To 5V Dc/Dc Converter Circuits Diagram

Build a 3V Battery To 5V Dc/Dc Converter Circuits Diagram

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Thursday, January 9, 2014

Sound Activated Lights

This diy sound activated lights circuit turns a lamp ON for a short duration when the dog barks (or a relatively strong sound) giving an impression that the occupants have been alerted. The condenser microphone fitted in a place to monitor sound and generates AC signals, which pass through DC blocking capacitor C1 to the base of transistor BC549 (T1). Transistor T1 along with transistor T2 amplifies the sound signals and provides current pulses from the collector of T2. When sound is produced in front of the condenser mic, triac1 (BT136) fires, activates lights and the bulb (B1) glows for about two minutes.

Assemble the sound activated lights circuit on a general purpose PCB (circuit board) and enclose in a plastic cabinet. Power to the sound activated switch circuit can be derived from a 12V, 500mA step-down transformer with rectifier and smoothing capacitor. Solder the triac ensuring sufficient spacing between the pins to avoid short circuit. Fix the unit in the dog’s cage or close to the sound monitoring spot, with the lamp inside or outside as desired. Connect the microphone to the sound activated lights circuit using a short length of shielded wire. Enclose the microphone in a tube to increase its sensitivity.

Caution:
 Since the sound activated lights uses 230V AC, many of its points are at AC mains voltage. It could give you lethal shock if you are not careful. So if you don’t know much about working with line voltages, do not attempt to construct this circuit. We will not be responsible for any kind of resulting loss or damage.
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Audio Amplifier


This audio amplifier circuit delivers up to 200 W of top-class quality for loudspeaker from 4 to 16 ohm. Operating voltage is between 24 and 36 V, max 5 A. The frequency response is from 20 to 20000 Hz.
Please take special care that the transistors and the IC’s have been fixed firmly and solely one or two separated cooling elements with sufficient dimensions for this purpose (thermal resistance < 1K/W).

200W Power Amplifier circuit diagram


Doing so it is necessary to mount the transistors and the IC’s insulated (with mica washes and plastic nipple). Please make sure before first operation that the transistors and the IC’s really do not have any electrical connection towards the cooling plate! The transistors have to be placed plane and firmly onto the cooling element! It is of extraordinary importance with this high-power amplifier that there is a considerable heat dissipation. The already mounted cooling element should be situated in a well ventilated case.
The PSU should be sufficiently powerful, power consumption of the amplifier may increase up to 5A. In case of using an unstabilised power supply. It is advisable to place a transformer of max 28V.
The amplifier will the show approx. 120W at a 4-Ohm loudspeaker, for it no-load voltage of the power supply will not be to high. If it is desired to use complete power, it is necessary to place a stabilised power supply with approx. 36V 5A. No-load voltage should not pass over 44V!
The cables leading the current supply and to the loudspeakers should have at least a cross section of min. 1.5 mm^2. The connected loudspeaker have to be equiped according to the high output power and should not have a lower impedance as 4 Ohm! With lower connection impedance and short circuit within the loudspeaker wiring, the transistors will be destructed.
The amplifier has an input sensitivity of approx. 500 … 800 mV. Therefore, it is possibile to connect directly at the amplifier tape decks, tuners, etc. In case there are connected signal sources with lower output voltage, it is necessary to pre-connect a preamplifier. Then it will alse be posible to connect microphones, etc.

200W audio amplifier PCB



Audio power amplifier components

IC1, IC2 = 2 IC’s TDA2030
T1, T3 = 2 transistors KT818 or BD708
T2, T4 = 2 transistors KT819 or BD705
C1, C2, C3, C4, C7 = 5 capacitors 150 nF
C5 = 1 elca 10uF 63V
C8 – 1 capacitor 1.8 nF
R1, R7, R9 = 3 resistances 100K
R2, R3, R10, R11 = 4 resistances 2.2 Ohm
R4, R5 = 2 res. 2K
R6, R8 = 2 res. 1 Ohm
R12, R13 = 2 res. 2 res. 3.3K
D1…D4 = 1N4001, 1N4002, 1N4003
1 PCB board approx 56×51 mm



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