Thursday, December 19, 2013
The expert group is making every effort to enhance the design of the Cell Phone Jammers system
The expert group is making every effort to enhance the design of the Cell Phone Jammers system.
The standard test signal I1: is GsM modulated carrier signal, and its structure in accordance with the GSM signal burst (burst, as burst or short burst. Below) structure, but its all modulation bits (including the burst of part of the training sequence) are directly random or pseudo-random data stream. (5) The standard test signal I2: a standard GSM modulation signal, but with the C1 signal is different from the unexpected part of the training sequence of the standard GSM training sequence, but the burst of data bits (including bits 58 and 59) are random or pseudo-random data stream. Using the same standard RF cable and adapters, including adapters, including the requirements of the GSM bands between the channel loss is less than 0.5dB, loss of value of the difference is less than 0.2dB; DCS frequency band between the loss of each channel is less than 1dB, loss value difference is less than 0.3dB, with characteristic impedance adapter should be within 50 ± 5 ohms. The table will contain the result of quantity computation of Cell Phone Jammers .I use the above principles and interface technology to develop a project: Highway display guidance system. Installed on the highway in front of the LED display shows real-time road vehicle traffic situation and weather and climate conditions, advise and guide the driver, the correct driver. The use of the system to some extent, eliminate a lot of traffic hazards, thereby safeguarding the smooth flow of road safety and peoples lives and property. The system consists of the control center and several display screen. Control center in real time the latest information sent to the display. Building control center communication link with the display terminal, the traditional method of laying fiber optic cable with the cable or the realization, or build a private wireless network allowing wireless. Because of the special nature of the highway, the control center and the distance between the display terminal is usually very far, two programs must invest a lot of money and huge construction effort.
Typically, short message service SMS-based wireless data transmission monitoring and control system for a point to multipoint wireless two-way data communication and remote control system, shown in Figure 1. System control center or command center for data, from computer networks, databases, electronic map and GSM communication interface. The main control center complete the information and data transceiver and finishing: on the one hand, to receive various control points to upload information and data, and put them in the appropriate database and distributed to the appropriate monitoring computer in order to achieve the various monitoring points monitoring and management; another aspect, a computer control center monitors the response issued by the various monitoring points of the control information, and to the information issued to the corresponding control points to achieve the point of monitoring equipment for control purposes.
Continue Reading[..]
The standard test signal I1: is GsM modulated carrier signal, and its structure in accordance with the GSM signal burst (burst, as burst or short burst. Below) structure, but its all modulation bits (including the burst of part of the training sequence) are directly random or pseudo-random data stream. (5) The standard test signal I2: a standard GSM modulation signal, but with the C1 signal is different from the unexpected part of the training sequence of the standard GSM training sequence, but the burst of data bits (including bits 58 and 59) are random or pseudo-random data stream. Using the same standard RF cable and adapters, including adapters, including the requirements of the GSM bands between the channel loss is less than 0.5dB, loss of value of the difference is less than 0.2dB; DCS frequency band between the loss of each channel is less than 1dB, loss value difference is less than 0.3dB, with characteristic impedance adapter should be within 50 ± 5 ohms. The table will contain the result of quantity computation of Cell Phone Jammers .I use the above principles and interface technology to develop a project: Highway display guidance system. Installed on the highway in front of the LED display shows real-time road vehicle traffic situation and weather and climate conditions, advise and guide the driver, the correct driver. The use of the system to some extent, eliminate a lot of traffic hazards, thereby safeguarding the smooth flow of road safety and peoples lives and property. The system consists of the control center and several display screen. Control center in real time the latest information sent to the display. Building control center communication link with the display terminal, the traditional method of laying fiber optic cable with the cable or the realization, or build a private wireless network allowing wireless. Because of the special nature of the highway, the control center and the distance between the display terminal is usually very far, two programs must invest a lot of money and huge construction effort.
Typically, short message service SMS-based wireless data transmission monitoring and control system for a point to multipoint wireless two-way data communication and remote control system, shown in Figure 1. System control center or command center for data, from computer networks, databases, electronic map and GSM communication interface. The main control center complete the information and data transceiver and finishing: on the one hand, to receive various control points to upload information and data, and put them in the appropriate database and distributed to the appropriate monitoring computer in order to achieve the various monitoring points monitoring and management; another aspect, a computer control center monitors the response issued by the various monitoring points of the control information, and to the information issued to the corresponding control points to achieve the point of monitoring equipment for control purposes.
Mini Ups System
This circuit provides an uninterrupted power supply (UPS) to operate 12V, 9V and 5V DC-powered instruments at up to 1A current. The backup battery takes up the load without spikes or delay when the mains power gets interrupted. It can also be used as a workbench power supply that provides 12V, 9V and 5V operating voltages. The circuit immediately disconnects the load when the battery voltage reduces to 10.5V to prevent deep discharge of the battery. LED1 indication is provided to show the full charge voltage level of the battery. miniature white LEDs (LED2 and LED3) are used as emergency lamps during power failure at night.
Mini Ups System Circuit diagram:
A standard step-down transformer provides 12V of AC, which is rectified by diodes D1 and D2. Capacitor C1 provides ripple-free DC to charge the battery and to the remaining circuit. When the mains power is on, diode D3 gets forward biased to charge the battery. Resistor R1 limits the charging current. Potentiometer VR1 (10k) with transistor T1 acts as the voltage comparator to indicate the voltage level. VR1 is so adjusted that LED1 is in the ‘off’ mode. When the battery is fully charged, LED1 glows indicating a full voltage level of 12V.
When the mains power fails, diode D3 gets reverse biased and D4 gets forward biased so that the battery can automatically take up the load without any delay. When the battery voltage or input voltage alls below 10.5V, a cut-off circuit is used to prevent deep discharging of the battery. Resistor R3, zener diode ZD1 (10.5V) and transistor T2 form the cut-off circuit. When the voltage level is above 10.5V, transistor T2 conducts and its base becomes negative (as set by R3, VR2 and ZD1). But when the voltage reduces below 10.5V, the zener diode stops conduction and the base voltage of transistor T2 becomes positive. It goes into the ‘cut-off’ mode and prevents the current in the output stage. Preset VR2 (22k) adjusts the voltage below 0.6V to make T2 work if the voltage is above 10.5V.
When power from the mains is available, all output voltages—12V, 9V and 5V—are ready to run the load. On the other hand, when the mains power is down, output volt-ages can run the load only when the battery is fully charged (as indicated by LED1). For the partially charged battery, only 9V and 5V are available. Also, no output is available when the voltage goes below 10.5V. If battery voltage varies between 10.5V and 13V, output at terminal A may also vary between 10.5V and 12V, when the UPS system is in battery mode.
Outputs at points B and C provide 9V and 5V, respectively, through regulator ICs (IC1 and IC2), while output A provides 12V through the zener diode. The emergency lamp uses two ultra-bright white LEDs (LED2 and LED3) with current limiting resistors R5 and R6. The lamp can be manually switched ‘on’ and ‘off’ by S1. The circuit is assembled on a general purpose PCB. There is adequate space between the components to avoid overlapping. heat sinks for transistor T2 and regulator ICs (7809 and 7805) to dissipate heat are used.
The positive and negative rails should be strong enough to handle high current. Before connecting the circuit to the battery and transformer, connect it to a variable power supply. Provide 12V DC and adjust VR1 till LED1 glows. After setting the high voltage level, reduce the voltage to 10.5V and adjust VR2 till the output trips off. After the settings are complete, remove the variable power sup-ply and connect a fully-charged battery to the terminals and see that LED1 is on. After making all the adjustment connect the circuit to the battery and transformer. The battery used in the circuit is a 12V, 4.5Ah UPS battery.
Source : http://www.ecircuitslab.com/2012/05/mini-ups-system.html
Wednesday, December 18, 2013
Build a Regulated Charge Pump Circuit Diagram
How to Build a Regulated Charge Pump Circuit Diagram. The dc-dc converter substitutes a voltage triplet in place of the external inductor and the diode that`s typically associated with the switching regulator, IC1. Inverting and non inverting amplifiers in the MOS-FET-driver (IC2) activate a diode-capacitor tripling network (D1 through D3, CI through C3).
A 50-kHz oscillator residing within IC1 produces the EXT signal (pin 6), IC2 converts this signal into drive signals (180° out of phase) for the tripler. The resulting charge-discharge action in the capacitors recharges C3 toward 10 V every 20 The ferrite bead limits output ripple to about 20-mVpp for a 50-mA load. Conversion efficiency is about 70% for the 5-V input, 10-V output configuration.
Regulated Charge Pump Circuit Diagram
Simple 12 Volt 30 Amp PSU Circuit Diagram
Using a single 7812 IC voltage regulator and multiple outboard pass transistors, this power supply can deliver output load currents of up to 30 amps. The design is shown below:
Simple 12 Volt 30 Amp PSU Circuit Diagram
Notes:
The input transformer is likely to be the most expensive part of the entire project. As an alternative, a couple of 12 Volt car batteries could be used. The input voltage to the regulator must be at least several volts higher than the output voltage (12V) so that the regulator can maintain its output. If a transformer is used, then the rectifier diodes must be capable of passing a very high peak forward current, typically 100amps or more. The 7812 IC will only pass 1 amp or less of the output current, the remainder being supplied by the outboard pass transistors. As the circuit is designed to handle loads of up to 30 amps, then six TIP2955 are wired in parallel to meet this demand.
The input transformer is likely to be the most expensive part of the entire project. As an alternative, a couple of 12 Volt car batteries could be used. The input voltage to the regulator must be at least several volts higher than the output voltage (12V) so that the regulator can maintain its output. If a transformer is used, then the rectifier diodes must be capable of passing a very high peak forward current, typically 100amps or more. The 7812 IC will only pass 1 amp or less of the output current, the remainder being supplied by the outboard pass transistors. As the circuit is designed to handle loads of up to 30 amps, then six TIP2955 are wired in parallel to meet this demand.
The dissipation in each power transistor is one sixth of the total load, but adequate heat sinking is still required. Maximum load current will generate maximum dissipation, so a very large heat sink is required. In considering a heat sink, it may be a good idea to look for either a fan or water cooled heat sink. In the event that the power transistors should fail, then the regulator would have to supply full load current and would fail with catastrophic results. A 1 amp fuse in the regulators output prevents a safeguard. The 400mohm load is for test purposes only and should not be included in the final circuit. A simulated performance is shown below:
Circuit Diagram
Calculations:
This circuit is a fine example of Kirchoffs current and voltage laws. To summarise, the sum of the currents entering a junction, must equal the current leaving the junction, and the voltages around a loop must equal zero. For example, in the diagram above, the input voltage is 24 volts. 4 volts is dropped across R7 and 20 volts across the regulator input, 24 -4 -20 =0. At the output :- the total load current is 30 amps, the regulator supplies 0.866 A and the 6 transistors 4.855 Amp each , 30 = 6 * 4.855 + 0.866. Each power transistor contributes around 4.86 A to the load. The base current is about 138 mA per transistor. A DC current gain of 35 at a collector current of 6 amp is required.
This circuit is a fine example of Kirchoffs current and voltage laws. To summarise, the sum of the currents entering a junction, must equal the current leaving the junction, and the voltages around a loop must equal zero. For example, in the diagram above, the input voltage is 24 volts. 4 volts is dropped across R7 and 20 volts across the regulator input, 24 -4 -20 =0. At the output :- the total load current is 30 amps, the regulator supplies 0.866 A and the 6 transistors 4.855 Amp each , 30 = 6 * 4.855 + 0.866. Each power transistor contributes around 4.86 A to the load. The base current is about 138 mA per transistor. A DC current gain of 35 at a collector current of 6 amp is required.
This is well within the limits of the TIP2955. Resistors R1 to R6 are included for stability and prevent current swamping as the manufacturing tolerances of dc current gain will be different for each transistor. Resistor R7 is 100 ohms and develops 4 Volts with maximun load. Power dissipation is hence (4^2)/200 or about 160 mW. I recommend using a 0.5 Watt resistor for R7. The input current to the regulator is fed via the emitter resistor and base emitter junctions of the power transistors. Once again using Kirchoffs current laws, the 871 mA regulator input current is derived from the base chain and the 40.3 mA flowing through the 100 Ohm resistor. 871.18 = 40.3 + 830. 88. The current from the regulator itself cannot be greater than the input current. As can be seen the regulator only draws about 5 mA and should run cold.
Tuesday, December 17, 2013
Protection For Telephone Line Circuit
A long time ago when telephones were so simple almost nothing could go amiss from an electrical point of view, Telecom operators installed surge protection on all telephone lines exposed to storm risks. Paradoxically, now that we are hooking up delicate and expensive equipment such as telephones filled with electronics, fax machines, (A)DSL modems, etc., this protection has disappeared.
However, if you have the good fortune to live in the countryside in a building served by overhead telephone lines, there’s an obvious risk of very high voltages being induced on the lines during thunderstorms. While we have lost count today of all of the modems, fax machines and other telephones that have been destroyed by a ‘bolt of lightning’, surprisingly you only have to invest a few pounds to get a remarkably efficient protection device like the one we are proposing here.
During a storm, often with lightning striking near a telephone line, the line carries transient voltages up to several thousands of volts. Contrary to the HV section of television sets or electrical fences, on which practically no current is running, in the case of lighting striking current surges of thousand of amps are not uncommon. To protect oneself from such destructive pulses, traditional components are not powerful or fast enough.
As you can see on our drawing, a (gas-filled) spark gap should be used. Such a component contains three electrodes, insulated from each other, in an airtight cylinder filled with rare gas. As long as the voltage present between the electrodes is below a certain threshold, the spark gap remains perfectly passive and presents an impedance of several hundreds of MW. On the other hand, when the voltage rises above this threshold, the gas is very rapidly ionized and the spark-gap suddenly becomes a full conductor to the point of being able to absorb colossal currents without being destroyed.
Protection Circuit Diagram For Telephone Line :
The one we are using here, whose size is of the same magnitude as an ordinary one watt resistor, can absorb a standardized 5,000 amps pulse lasting 8/20 ms! Since we are utilizing a three-electrode spark gap, the voltage between the two wires of the line or between any wire and ground, cannot exceed the sparking voltage, which is about 250 volts here. Such protection could theoretically suffice but we preferred to add a second security device made with a VDR (GeMOV or SiOV depending on the manufacturer), which also limits the voltage between line wires to a maximum of 250 volts.
Even if this value seems high to you, we should remember that all of the authorized telephone equipment, carrying the CE mark must be able to withstand it without damage. This is not always the case however with some low-end devices made in China, but that’s an entirely different problem. Since pulses generated by lightning are very brief, the ground connection of our assembly must be as low-inductance as possible.
It must therefore be short, and composed of heavy-duty wire (1.5 mm2 c.s.a. is the minimum). If not, the coil, composed of the ground connection, blocks the high frequency signal that constitutes the pulse and reduces the assembly’s effectiveness to nothing. Finally, please note that this device obviously has no effect on the low frequency signals of telephones and fax machines and it does not disturb (A)DSL signals either.
Author: Christian Tavernier - Copyright: Elektor Electronics Magazine
Build Motorcycle Alarm Circuit Diagram
This is a Motorcycle Alarm Circuit Diagram. Any number of normally open switches may be used. Fit the mercury switches so that they close when the steering is moved or when the bike is lifted off its side-stand or pushed forward off its center-stand. Use micro-switches to protect removable panels and the lids of panniers etc. While at least one switch remains closed, the siren will sound.
Motorcycle Alarm Circuit Diagram
About tw1o minutes after the switches have been opened again, the alarm will reset. How long it takes to switch off depends on the characteristics of the actual components used. But, up to a point, you can adjust the time to suit your requirements by changing the value of C1.The circuit board and switches must be protected from the elements. Dampness or condensation will cause malfunction.Without its terminal blocks, the board is small. Ideally, you should try to find a siren with enough spare space inside to accommodate it. Fit a 1-amp in-line fuse close to the power source.
This protects the wiring. Instead of using a key-switch you can use a hidden switch; or you could use the normally closed contacts of a small relay. Wire the relay coil so that it is energized while the ignition is on. Then every time you turn the ignition off, the alarm will set itself.When it`s not sounding, the circuit uses virtually no current. This should make it useful in other circumstances. For example, powered by dry batteries and with the relay and siren voltages to suit, it could be fitted inside a computer or any thing else that`s in danger of being picked up and carried away. The low standby current and automatic reset means that for this sort of application an external on/off switch may not be necessary.
cell phone jammer will not intercept on the base station
cell phone jammer will not intercept on the base station.
Visible, smart phones, large screen, large screen products favored by the users. Chinese mobile phone market in June 2011, the smart phone market with different screen sizes attention to the proportion of contrast. Case Study: Apples share of continued expansion. Apples global handset market share continued to expand. According to the U.S. market research firm Gartner statistics show that, since 2007, Apple introduced the iPhone smart phone, smart phone market, the pattern began to change. In 2008, Apple alone an iPhone, the global market share has reached 8.2 percent, while the first quarter of 2011, only three years, alone, four generations of iPhone products, Apples market share has reached 16.8%, to become the worlds first The three operating systems. cell phone jammer will just influence the downlink.
2007-2011Q1 Apple Worldwide sales of mobile phones and smart phone market share trend. Data sources Gartner, data management: ZDC. Apple user attention in the smart phone market in China is climbing. Rattling trend in the global mobile phone market with Apple, the Apple in the smartphone market, but also showed the fierce attacks, especially in cooperation with China Unicom, Apple users attention from record highs. The ZDC monitoring data show that the smart phone market in China in June 2011, Apple accounted for 9.2 percent of the concern proportion, only a difference of 2.6 percent and Motorola. In addition, from Apple released the data, the establishment of the ecosystem and no brand. This is a considerate design for cell phone jammer .
Since 2011, the three operators for 3G mobile terminals, a number of Central Purchasing universal low-priced products has always been an important source of new 3G subscribers, new subscribers expected to reach the end of universal terminal undoubtedly become the focus of the tender object, and an important platform to promote value-added services as operators necessary to support the role of popular intelligent terminal to enhance 3G users overall ARPU value are bound to become the top priority of purchases and sales. Sino Market monitoring data show that in October this year, 3G smart market 700 to 1500 the proportion of the price reached 54.7%, 24.6% increase compared to same period last year, up significantly. The insulation feature of cell phone jammer is very important for the customer.Products, the number of 3G thousands of intelligent machines models increase from 15 in October 2010 to October 2011, 123 models, thousands of intelligent machines has become a new force of the smart phone market. The low-end market into focus. IPhone users and thousands of intelligent machines the user using the data flow to compare, you can find iPhone users monthly data traffic is not significantly higher.
Continue Reading[..]
Visible, smart phones, large screen, large screen products favored by the users. Chinese mobile phone market in June 2011, the smart phone market with different screen sizes attention to the proportion of contrast. Case Study: Apples share of continued expansion. Apples global handset market share continued to expand. According to the U.S. market research firm Gartner statistics show that, since 2007, Apple introduced the iPhone smart phone, smart phone market, the pattern began to change. In 2008, Apple alone an iPhone, the global market share has reached 8.2 percent, while the first quarter of 2011, only three years, alone, four generations of iPhone products, Apples market share has reached 16.8%, to become the worlds first The three operating systems. cell phone jammer will just influence the downlink.
2007-2011Q1 Apple Worldwide sales of mobile phones and smart phone market share trend. Data sources Gartner, data management: ZDC. Apple user attention in the smart phone market in China is climbing. Rattling trend in the global mobile phone market with Apple, the Apple in the smartphone market, but also showed the fierce attacks, especially in cooperation with China Unicom, Apple users attention from record highs. The ZDC monitoring data show that the smart phone market in China in June 2011, Apple accounted for 9.2 percent of the concern proportion, only a difference of 2.6 percent and Motorola. In addition, from Apple released the data, the establishment of the ecosystem and no brand. This is a considerate design for cell phone jammer .
Since 2011, the three operators for 3G mobile terminals, a number of Central Purchasing universal low-priced products has always been an important source of new 3G subscribers, new subscribers expected to reach the end of universal terminal undoubtedly become the focus of the tender object, and an important platform to promote value-added services as operators necessary to support the role of popular intelligent terminal to enhance 3G users overall ARPU value are bound to become the top priority of purchases and sales. Sino Market monitoring data show that in October this year, 3G smart market 700 to 1500 the proportion of the price reached 54.7%, 24.6% increase compared to same period last year, up significantly. The insulation feature of cell phone jammer is very important for the customer.Products, the number of 3G thousands of intelligent machines models increase from 15 in October 2010 to October 2011, 123 models, thousands of intelligent machines has become a new force of the smart phone market. The low-end market into focus. IPhone users and thousands of intelligent machines the user using the data flow to compare, you can find iPhone users monthly data traffic is not significantly higher.
Subscribe to:
Posts (Atom)