Diagram Diagosis

The antenna of mobile phone jammer should be perpendicular to the ground
Introduced Vodafone (LSE: VOD NYSE: VOD) (Vodafone) is a multinational mobile phone operators. Newbury (Newbury), headquartered in Berkshire County, England and Dusseldorf, Germany. Is currently one of the worlds largest mobile telecommunications network company, have investments in 27 countries around the world. Do co-operate with the local mobile phone operators in 14 countries, the mobile phone network of associates. As of December 31, 2004, Vodafone has about 151.8 million users in the world. Vodafone Vodafone Group as the name listed on the London Stock Exchange (code VOD.L) and the NYSE (symbol VOD). mobile phone jammer can be installed in the ceiling in the hall.
AT & T will be the "information superhighway" the plan participants. Will achieve the ideal of mankind - the establishment of a global information service system, so that people anywhere convenient to contact, the sharing of information resources to meet the advent of the information society. Germany Vodafone vodafone Vodafone (in vodafone KK) is the worlds largest mobile communications operator, and its network covering 26 countries, and to provide network services in 31 countries and their partners, over 179 million users worldwide. Vodafone has the worlds most comprehensive enterprise information management systems and customer service systems, service delivery, increase customer has a strong advantage in creating value. Here will show the bulk shielding of mobile phone jammer in a building.
In addition to Spains four stock (Madrid, Barcelona, Bilbao and Valencia), Spain, the telephone companys stock is still in London, Paris, Frankfurt, Tokyo, New York, Sao Paulo, Limas stock market and London the SEAQ International stock trading system to trade. In order to remain invincible in the fierce competition in international telecommunications market, the telephone company in Spain organized a series of international business lines, operated by an independent company. Such a flexible management style is conducive to take measures according to their characteristics, can also enhance the financial strength through joint ventures. Not long ago, the Spanish telephone company into the Internet field, by the same company responsible for production and sales operations. Shielding effect of mobile phone jammer is dependent on room size.
Meanwhile, Cisco Systems, Inc. is building the backbone of the Internet, more than 80 percent of the Internet backbone routers is Cisco Systems, the companys products. Texas Instruments (TI) - Texas Instruments Incorporated is a global semiconductor company, is the world leader in digital signal processing and analog technologies and suppliers, the semiconductor engines of the Internet age. The worlds first integrated circuit (IC) was invented by TI engineer Jack Kilby. The company is headquartered in Dallas, Texas, its business, including semiconductor, industrial, electronic materials, educational products. Companies in over 25 countries worldwide and has manufacturing or sales organization. In this method, there is no need to install mobile phone jammer on the outer wall of every floor.

Aburst water-supply hose of the washing machine, a bathroom tap that you forgot to close, or a broken aquarium wall may turn your house into a pond. You can avoid this mess by using an electronic water alarm that warns you of the water leakage as soon as possible. The acoustic water alarm circuit presented here takes advantage of the fact that the tap water is always slightly contaminated (or has salts and minerals) and thus conducts electricity to a certain extent.

It is built around IC LMC555 (IC1), which is a CMOS version of the bipolar 555 timer chip. IC1 is followed by a complementary pair of emitter followers (T1 and T2) to drive a standard 8-ohm speaker (LS1). Power is supplied by a compact 9V PP3 battery. Power is applied when power switch S1 is closed. The reset input (pin 4) of IC1 is held low by resistor R1 (2.2-kilo-ohm).

The astable oscillator wired around IC1 is in disabled mode. When probes P1 and P2 become wet, these conduct to reverse the state of IC1’s reset terminal. As a result, the astable multivibrator starts oscillating at a frequency determined by resistor R2 and capacitor C3. The output of IC1 drives the complementary pair of transistors T1 and T2.

Electronic Water Alarm Circuit Diagram

Although this combination causes significant crossover distortion, it doesn’t have any adverse effect on the square-wave audio signal processing. A 10-kilo-ohm potentiometer (VRI) is inserted between output pin 3 of IC1 and the bases of transistors T1 and T2 for volume control. The probes can be made using two suitable copper needles or small pieces of circuit board with the copper surface coated with solder.

Fit these at the lowest point where water will accumulate. After construction, place the alarm circuit well away from the point of possible leakage. Use a pair of thin twisted flexible wires to connect the probes to the circuit. Capacitor C1 connected across IC1 input (pin 4 and GND) keeps the alarm circuit from responding to stray electrostatic fields.

Similarly, twisting the wires together makes the relatively long connection between the probes and the circuit less sensitive to false alarms due to external electromagnetic interference. Finally, if you want to lower the probe sensitivity, reduce the value of grounding resistor R1.

Cell Phone Jammers has no radiation towards the human body.
Although almost all manufacturers have in recent years tend to use lithium-ion battery, but the worlds major mobile phone manufacturers the choice of battery or have their own characteristics and habits, such as once in the same historical period: Nokia: The Ni- MH (nickel-metal hydride) battery, LiB (liquid lithium-ion) batteries, not the use of LiP (polymer lithium-ion) batteries. Ericsson: The Ni-MH battery, LiB battery, LiP batteries. Motorola: The Ni-MH battery, LiB battery, did not use LiP batteries. Not difficult to find, from the earliest use of mobile phones LiP polymer lithium-ion batteries on this matter, Ericsson reflect the true nature of their cell phone technology pioneer. According to the information I find that, at present polymer lithium-ion battery factory in Japan SONY, Panasonic, GS, several companies, produced in 2000 reached 21 million, of which 50% of Ericsson mobile phone support. 
This environment is very noisy radio environments, it is even more obvious advantages. Another advantage of Bluetooth technology is that it applies globally consistent set of frequencies, which eliminates the "border" barriers, while in the field of cellular mobile phones, this obstacle has been plagued users for many years. In addition, ISM band radio system for all the bands are open, so use one of these bands will encounter unpredictable sources of interference. For example, some appliances, cordless phones, car room door openers, microwave ovens, etc., are likely to be interference. The inspection report of Cell Phone Jammers needs the signature of the director of Cell Phone Jammers workshop.
To this end, the Bluetooth technology, especially designed to quickly identify and frequency hopping scheme to ensure that the link stability. Band frequency hopping is to be divided into a number of hopping channels (hop channel), in a single connection, the radio transceiver according to a certain code sequence constantly jump from one channel to another channel, only the sender and receiver to communicate is based on the law , and other interference can not be carried out by the same laws of interference; hopping the instantaneous bandwidth is very narrow, but through spread spectrum technology make this expansion into narrowband or broadband multiply, so that interference effects may become very small. Work with other systems compared to the same frequency band, Bluetooth frequency hopping faster, shorter packets, which makes Bluetooth technology are more stable than other systems. Chipset mainly refers to the Bluetooth headset Bluetooth chips used in the design of the composition. Bluetooth chip on the market today many manufacturers. Major telecommunications manufacturers have designed in accordance with Bluetooth standards have different chipsets. The factory inspection and acceptance personnel should sign the report of Cell Phone Jammers if Cell Phone Jammers is qualified.

The Philips Semiconductors TDA8551 is a small audio amplifier with an integrated volume control. When operated from +5 V, it delivers a nominal output power of more than one watt into 8 ohms. It can also be used over a supply voltage range of +2.7 to +5.5 V, with correspondingly reduced output power. The output volume can be adjusted from –60 dB to +20 dB in 64 steps, using a set of up and down push-buttons. The shared UP/DOWN input for the up and down switches has three states. If it is ‘floating’, which means that both of the switches are open, the volume remains unchanged. A pulse to earth decreases the volume by 1.25 dB, while a positive pulse increases the volume by 1.25 dB.

When the power is switched on, the internal counter takes on the –20 dB setting. An additional input (MODE) allows the amplifier to be switched from the operating state to the mute or standby state. If this input is held at the earth level, the amplifier is operational. If +5 V is applied to this pin, the TDA8551 enters the Standby mode, in which the current consumption drops from the typical operational level of 6mA to less than 10µA. Finally, the MODE input can be used as a mute input by applying a voltage of 1 t0 3.6 V to this input. This voltage can be provided by a connection to the SCR pin, which lies at half of the operating voltage and to which a filter capacitor is connected.

The loudspeaker is connected in a floating configuration between the two outputs of the bridge amplifier in the TDA8551. This provides the desired output power level, in spite of the low supply voltage. For headphone applications, which do not need as much output power, you can connect the headphone between earth and one of the outputs, via an electrolytic coupling capacitor. You can make a stereo headphone amplifier in this way, using two TDS8551 ICs. The TDA8551 is housed in a DIP8 package. The SMD version is the TDA8551T, in an SO8 package.

Cordless telephones are very popular nowadays. But they have a major drawback, i.e. they cannot be operated during power failure. Therefore usually another ordinary telephone is connected in parallel to the cordless telephone. This results in lack of secrecy. UPS is a permanent solution to this problem. Since the UPS is meant only for the cordless telephone, its output power is limited to around 1.5W. This is sufficient to operate most cordless telephones. as these employ only small capacity adapters (usually 9V/12V, 500mA), to enable the operation of the circuit and to charge the battery present in the handset. The UPS presently designed is of online type. Here the inverter is ‘on’ throughout, irrespective of the presence of the AC mains.

When the AC mains is present, the same is converted into DC and fed to the inverter. A part of the mains rectified output is used to charge the battery. When the mains power fails, the DC supply to the inverter is from the battery and from this is obtained AC at the inverter output. This is shown in fig.1. The circuit wired around IC CD4047 is an astable multivibrator operating at a frequency of 50 Hz. The Q and Q outputs of this multivibrator directly drive power MOSFETS IRF540. The configuration used is push-pull type. The inverter output is filtered and the spikes are reduced using MOV (metal oxide varistor). The inverter transformer used is an ordinary 9V-0-9V, 1.5A mains transformer readily available in the market.

Two LEDS (D6 and D7) indicate the presence of mains/battery. The mains supply (when present) is stepped down, rectified and filtered using diodes D1 through D4 and capacitor C1. A part of this supply is also used to charge the battery. In place of a single 12V, 4Ah battery, one may use two 6V, 4Ah batteries (SUNCA or any other suitable brand). The circuit can be easily assembled on a general-purpose PCB and placed inside a metal box. The two transformers may be mounted on the chassis of the box. Also, the two batteries can be mounted in the box using supporting clamps. The front and back panel designs are shown in the Fig. 3. The same circuit can deliver up to 100W, provided the inverter transformer and charging transformer are replaced with higher current rating transformers, so that the system can be used for some other applications as well.

The FMS6363 Low Cost Video Filter (LCVF) provides 6dB gain from input to  output. In addition, the input will be slightly offset to optimize the output driver performance. The FMS6363 provides an internal diode clamp to support AC-coupled input signals. If the input signal does not go below ground, the input clamp will not operate. This allows DAC outputs to directly drive the FMS6363 without and AC coupling capacitor (usually 220 ?F). The offset is held to the minimum required value to decrease the standing DC current into the load.

The present tester is intended primarily for testing the 24 V electrical circuits found on most pleasure craft. However, if the resistors are given different values, the circuit may, of course, be used for other voltage ranges. For 12 V, the value of the resistors should be 1.2 k?, and for 48 V, 4.7 k?. The tester should be connected to the +ve and –ve voltage rails with test clips or crocodile clips, whereupon the test probe is placed on the point to be tested. When the potential at the point is positive, the red LED lights; if it is negative, the green one does. If the supply is not connected to earth, the tester may be used as ground-leak tester. In this situation, one of the LEDs lights when the test probe touches a point at earth potential and there is a leakage.

Most small internal-combustion engines commonly used in the model-building world use glow plugs for starting. Unfortunately, glow plugs have an operating voltage of 1.5 V, while fuel pumps, starter motors, chargers and the like generally run on 12 V. This means that a separate battery is always needed to power the glow plug. The standard solution is to use an additional 2-V lead storage battery, with a power diode in series to reduce the voltage by approximately 0.5 V. However, this has the annoying consequence that more than 30 percent of the energy is dissipated in the diode. Naturally, this is far from being efficient. The converter presented here allows glow plugs to be powered from the 12-V storage battery that is usually used for fuelling, charging, starting and so on.

A car battery can also be used as a power source. Furthermore, this circuit is considerably more efficient than the approach of using a 2-V battery with a series power diode. The heart of the DC/DC converter is IC1, a MAX 1627. The converter works according to the well-known step-down principle, using a coil and an electrolytic capacitor. Here the switching stage is not integrated into the IC, so we are free to select a FET according to the desired current level. In this case, we have selected a 2SJ349 (T1), but any other type of logic-level FET with a low value of RDSon would also be satisfactory. Of course, the FET must be able to handle the required high currents. Diode D1 is a fast Schottky diode, which must be rated to handle the charging currents for C2 and C3. This diode must also be a fairly hefty type. The internal resistances of coil L1 and capacitors C2 and C3 must be as low as possible. This ensures efficient conversion and prevents the components from becoming too warm. The resistor network R2/R3 causes 87 percent of the output voltage to be applied to the FB pin of IC1.

This means that an output voltage of 1.5 V will cause a voltage of approximately 1.3 V to be present at the FB pin. The IC always tries to drive the switching stage such that it ‘sees’ a voltage of 1.3 V on the FB input. If desired, a different output voltage can be provided by modifying the values of R2 and R3. When assembling the circuit, ensure that C5 and C1 are placed as close as possible to IC1, and use sufficiently heavy wiring between the 12-V input and the 1-5-V output, since large currents flow in this part of the circuit. A glow plug can easily draw around 5 A, and the charging current flowing through the coil and into C2 and C3 is a lot higher than this!

circuit diagram of burglar alarm using IC timer 555/556 is functioned as an alarm to prevent thief entering your house. The alarm would produce loud sound when a thin wire connecting resistor R1 with IC pin no 4 is broken. Thin fiber is used as the wire. The thinner the wire, the more responsive the alarm. This circuit needs 5-15V power supply, buzzer is used as a speaker. Here is the circuit schematic :

Parts list :

•     Resistor R1 : 10k
•     Resistor R2 : 68k
•     Resistor R3 : 1k
•     Polar capacitor C1 : 1uF/15 B
•     Capacitor C2-C3 : 0.01uF
•     IC Timer : NE555

Derived from the Two-wire Lamp Flasher design, hosted on RED Free Circuit Designs since 1999, this astonishingly simple circuit allows one or two powerful 12V 21W car bulbs to be driven in flashing mode by means of a power MosFet.
Devices of this kind are particularly suited for road, traffic and yard alerts and in all cases where mains supply is not available but a powerful flashing light is yet necessary.

Circuit Diagram:

Car Bulb Power Flasher  Circuit Diagram

 

Notes:

• Flashing frequency can be varied within a limited range by changing C1 value.
• As high dc currents are involved, please use suitably sized cables for battery and bulb(s) connections.

Source : www.redcircuits.com

A difficult problem in the design of conventional stereo tone controls is obtaining synchronous travel of the potentiometers. Even a slight error in synchrony can cause phase and amplitude differences between the two channels. Moreover, linear potentiometers are often used in such controls, and these give rise to unequal performance by human hearing. Special potentiometers that counter these difficulties are normally hard to obtain in retail shops. A good alternative is a control based on a rotary switch and a discrete potential divider. The problem with this that for good tone control more than six steps are needed, and switches for this are also not readily available. Fortunately, electronic circuits can remove these difficulties.

The analogue selectors used may be driven by mechanical switches, standard logic circuit or a microcontroller. The selectors used in the present circuit are Type SSM2404 versions from Analogue Devices, which switch noiselessly. Each IC contains four selectors, so that a total of eight are used. The step size is 1.25 dB at 20 Hz with a maximum of 10dB . The circuit can be mirrored with S1, which means that a selection may be made of amplification or attenuation of bass frequencies. The user can choose between attenuation only and extending the range by dividing R9. The control can be bridged by switch S2.

To prevent the output impedance of the circuit having too much effect on the operation of the circuit, the output impedance must be ≤ 10 Ω. Resistor R1 2 protects the circuit against too small a load. At maximum bass amplification at Ui n = 1 V r.m.s., the THD+N <0.001% for a frequency range of 20 Hz to 20kHz and and a bandwidth of 80kHz. The circuit draws a current of about 10 mA.

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