Friday, December 27, 2013
The shell design of mobile phone jammer is unique
The
shell design of mobile phone jammer is unique.
RF chip: Due to the different design ideas for mobile phone manufacturers as part of using a set of to ADI logic and radio frequency (IF IC AD6523 and the frequency synthesizer AD6524) chip, the
other part using only the of ADI logic chipset, while the RF chip other companies chips. Mobile client software to develop the greatest difficulty that is not unified platform mobile phone
development platform too. The phone can be divided into the smart phone and feather phone phone. The development platform can be divided into an open platform and closed platforms to open platforms
including symbian, windows mobile, linux, iPhone, Android, BlackBerry, j2me, brew, etc.. To ensure mobile phone jammer can run with high efficiency.
But the irony is that the site has tried to iPhone 4 fell from a height of 1 meter to go, the screen is immediately crushed, it seems normal or pay attention to popular brands. 2 buttons and
interface changes: new design of the SIM card slot translocation and volume buttons the top of the phone boot / lock button and 3.5mm headphone jack on the side of the button shape design changes
SIM card slot change to the phone right side and more listed before the iPad 3G version, iPhone 4 more compact Micro Sim card, SIM card slot from the top of the move to the right, while the
original one plus and minus volume keys become two separate keys. Border antenna. iPhone technology on a major change in the past, hidden the body inside the antenna change on the border of the
cell phone. The shell of mobile phone jammer takes use of the electric oxidization technology.
In the process of project management, project managers should be placed on the work of communication, mobile phone R & D projects are projects that require multi-sectoral collaboration of most sub
-projects are the projects of other departments, with varying degrees of impact. R & D process, there is no formal communication plan, most of the communication is only through oral or informal
forms of communication. Communication before the communication plan to communicate with staff without any preparation, even to communicate the result is that we do not know what they would like to
achieve. Communicate the results can not form a report, naturally there is no any information can be released. The key post project follow up on personnel selection, first and foremost must have a
sense of responsibility. mobile phone jammer is to ensure use of the machine.MTK platform operating system nucleus of the introduction of the nucleus of the Internet article "Nucleus Real Time
Operating System analysis report.
Continue reading...
shell design of mobile phone jammer is unique.
RF chip: Due to the different design ideas for mobile phone manufacturers as part of using a set of to ADI logic and radio frequency (IF IC AD6523 and the frequency synthesizer AD6524) chip, the
other part using only the of ADI logic chipset, while the RF chip other companies chips. Mobile client software to develop the greatest difficulty that is not unified platform mobile phone
development platform too. The phone can be divided into the smart phone and feather phone phone. The development platform can be divided into an open platform and closed platforms to open platforms
including symbian, windows mobile, linux, iPhone, Android, BlackBerry, j2me, brew, etc.. To ensure mobile phone jammer can run with high efficiency.
But the irony is that the site has tried to iPhone 4 fell from a height of 1 meter to go, the screen is immediately crushed, it seems normal or pay attention to popular brands. 2 buttons and
interface changes: new design of the SIM card slot translocation and volume buttons the top of the phone boot / lock button and 3.5mm headphone jack on the side of the button shape design changes
SIM card slot change to the phone right side and more listed before the iPad 3G version, iPhone 4 more compact Micro Sim card, SIM card slot from the top of the move to the right, while the
original one plus and minus volume keys become two separate keys. Border antenna. iPhone technology on a major change in the past, hidden the body inside the antenna change on the border of the
cell phone. The shell of mobile phone jammer takes use of the electric oxidization technology.
In the process of project management, project managers should be placed on the work of communication, mobile phone R & D projects are projects that require multi-sectoral collaboration of most sub
-projects are the projects of other departments, with varying degrees of impact. R & D process, there is no formal communication plan, most of the communication is only through oral or informal
forms of communication. Communication before the communication plan to communicate with staff without any preparation, even to communicate the result is that we do not know what they would like to
achieve. Communicate the results can not form a report, naturally there is no any information can be released. The key post project follow up on personnel selection, first and foremost must have a
sense of responsibility. mobile phone jammer is to ensure use of the machine.MTK platform operating system nucleus of the introduction of the nucleus of the Internet article "Nucleus Real Time
Operating System analysis report.
Thursday, December 26, 2013
Simple Alarm System
The circuit presented here is a very simple and yet highly effective alarm system for protecting an object. The circuit requires no special devices and can be built using components that you will no doubt be able to find in the junk box. The alarm-triggering element is a simple reed switch. To generate the alarm signal itself any optical or acoustic device that operates on 12 V can be used: for example a revolving light, a siren, or even both. In the quiescent state the reed switch is closed. As soon as the reed switch opens, the input to IC1.B will go low (previously the potential divider formed by R2 and R3 held the input at 5.17 V, a logic high level). A turn-on delay of between 0 and approximately 90 s can be set using P1, and a turn-off delay of between 0 and approximately 20 s can be set using P2. When the system is turned on (using S1), the turn-on delay is activated, giving the user of the system at most 90 s to leave the object alone before the system goes into the armed state, and the object is then protected.
Project image :
Simple Alarm System Project image
Once the reed switch opens the turn-off delay of at most 20 s starts: this allows the rightful owner of the object to turn the system off before the alarm is triggered. If some unauthorised per-son causes the reed switch to open, the alarm will be triggered after the turn-off delay. Also, even if the reed switch is briefly opened and then closed again, the alarm will still be triggered. Once the alarm is triggered, T3 will conduct for about 45 s (because of R8 and C5). The turning off of the alarm is necessary to avoid the nuisance caused by a permanently sounding alarm system. The system then returns to the armed state, which means that the next time the reed switch is opened the alarm will trigger again. If it is not desired that the duration of the alarm be limited, for example if a visual indication is used, D5 should not be fitted. The system can be extended by fitting multiple reed switches in series. As soon as any one is opened, the alarm is triggered.
Circuit diagram:
Simple Alarm System Circuit Diagram
When S1 is closed C3 charges via P1. Depending on the potentiometer setting, it takes between 0 and 90 s to reach the input threshold voltage of IC1.A. The output of IC1.A then goes low and D3 stops conducting. Assuming the reed switch is closed, the inputs of IC1.B stay high and the output therefore low. If the reed switch is opened after the turn-on delay expires the output of the gate will change state and turn on T1. This ensures that the output of the gate remains high even after the reed switch is closed again. C4 now starts charging via P2, reaching the input threshold voltage of IC1.C after between 0 and 20 s, again according to the potentiometer setting. The output of IC1.C goes low, and T2 and T3 are turned on — and the siren sounds. Any Darlington transistor can be used for T3. At the same time, C5 charges via R8, reaching the input threshold of IC1.D in about 45 s. When the output of IC1.D swings low, it pulls the inputs of IC1.A low via diode D5: the siren stops and the system returns to the armed state.
If the potentiometers P1 and P2 are replaced by fixed resistors it is possible to build the circuit small enough to fit in a match-box, without the need to resort to SMD components. This is ideal if the circuit is to be used to protect a motorbike. If the alarm system is to be used in a car, an existing door switch contact can be used instead of the reed switch. In this case an RC combination needs to be added to prevent false triggering. Use a 10 µF/25 V electrolytic for C6, a 100 kΩ resistor for R9 and a 1N4001 for D7. It is again possible to wire multiple door switch contacts in parallel: as soon as one contact closes, IC1.B will be triggered.
Source:http://www.ecircuitslab.com/2012/02/simple-alarm-system.html
Wednesday, December 25, 2013
Off line Fly back Regulator Circuit Diagram
This Off line Fly back Regulator Circuit Diagram uses a low-cost feedback scheme in which the dc voltage developed from the primary-side control winding is sensed by the UC1842 error amplifier. Load regulation is therefore dependent on the j coupling between secondary and control windings, and on transformer leakage inductance.
For applications requiring better load regulation, a UC1901 Isolated Feedback Generator can be used to directly sense the output voltage.
Off line Fly back Regulator Circuit Diagram
Tuesday, December 24, 2013
TV audio video transmitter Schematic Diagram
This is a simple TV audio video transmitter circuit can be constructed using this schematic diagram . This TV audio video transmitter circuit can be used to transmit video signals from VCR ( or some other device ) to a TV without using any cable .
Video signals input at jack J1 are first terminated by resistor R6 and coupled through capacitor C1 to clamping-diode D1. Potentiometer R3 is used to set the gain of the video signal; its effect is similar to that of the contrast control on a TV set.
TV audio video transmitter Schematic Diagram
Bias-control R7 can be used to adjust the black level of the picture so that some level of signal is transmitted, even for a totally dark picture.
RF-transformer T1 and its internal capacitor form the tank circuit of a Hartley oscillator thats tuned to 4.5 megahertz. Audio signals input at J2 are coupled to the base of Q3 via C2 and R4: the audio signal modulates the base signal of Q3 to form an audio subcarrier that‚s 4.5-megahertz higher than the video-carrier frequency.
The FM modulated subcarrier is applied to the modulator section through C5 and R9.
Resistor R9 adjusts the level of the subcarrier with respect to the video signal.
Resistor R9 adjusts the level of the subcarrier with respect to the video signal.
Transistors Q1 and Q2 amplitude modulate the video and audio signals onto an RF-carrier signal. The operating frequency is set by coil L4, which is 3.5 turns of 24- gauge enameled wire on a form containing a standard ferrite slug.
The RF output from the oscillator (L4, C7 and C9 ) section is amplified by Q5 and Q6, whose supply voltage comes from the modulator . Antenna matching and low-pass filtering is performed by C12, C13, and L1.
Resistor R12 is optional; it is added to help match the output signal to any kind of antenna.
To align this audio video transmitter you need to tune a TV receiver to an unused channel between 2 and 6. The TV must have an indoor antenna connected directly to it; an outdoor antenna or cable wont work. Make sure both potentiometers (R3, R7) are in middle position and apply power to the transmitter. Adjust L4 with a nonmetallic tool until the TV screen goes blank ,then fine-adjust L4 for the "most-blank" picture.
Connect the video and audio outputs from a VCR(AV source) to jacks J1 and J2 (respectively) of the transmitter .
After that you should see a picture on the TV screen: if you do, readjust L4 for the best picture; if you dont, check the board for any bad connections. Next, adjust R3 for the best picture brightness and R7 for the best overall picture.
Finally, adjust T1 with a nonmetallic tool for the best sound .
The TV transmitter combines line level audio and video signals, and transmits the resulting signal up to 300 feet. The circuit can be powered from a 9-12V power supply circuit .
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