Transceivers, appliances such as mobile phones that can send and receive messages, have become smaller and smaller over the last few years, but users are about to experience a new meaning in miniaturisation. Research at The Hong Kong University of Science & Technology (HKUST) has successfully combined a unique system architecture and new circuit design techniques to reduce them in size like never before. Principal Investigator Dr Howard Luong said the handset of a typical mobile phone today may contain between 150 and 300 separate electrical components. His research group proposed and demonstrated circuit techniques that make it possible to combine many of these components to a single chip and therefore to significantly reduce the size of circuitry (see example in graphic). A US patent has been granted for one of the circuit techniques. The transformation applies to the CMOS (Complimentary Metal-Oxide Semiconductor) manufacturing process, which can produ...
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The National Semiconductor LMV225 is a linear RF power meter IC in an SMD package. It can be used over the frequency range of 450 MHz to 2000 MHz and requires only four external components. The input coupling capacitor isolates the DC voltage of the IC from the input signal. The 10-k? resistor enables or disables the IC according to the DC voltage present at the input pin. If it is higher than 1.8 V, the detector is enabled and draws a current of around 5–8 mA. If the voltage on pin A1 is less than 0.8 V, the IC enters the shutdown mode and draws a current of only a few microampères. The LMV225 can be switched between the active and shutdown states using a logic-level signal if the signal is connected to the signal via the 10-kR resistor. Circuit diagram: Linear RF Power Meter Circuit Diagram The supply voltage, which can lie between +2.7 V und +5.5 V, is filtered by a 100nF capacitor that diverts residual RF signals to ground. Finally, there is an output capacitor that forms a...
Simple triangle-square wave oscillator circuit diagram . In this circuit by making Rt variable it is possible to alter the operating frequency over a 100 to 1 range Versatile triangle/square wave oscillator has a possible frequency range of 0 Hz to 100 kHz. Triangle Square wave Oscillator Circuit Diagram
LCD Interfacing: In this tutorial i will show you how to interface 16x2 LCD with micro-controller. 16x2 means there are two rows and each row contain maximum 16 characters. For more detail refer to the LCD datasheet, which you are using. Basic Connection: Applies 5v to pin 2 and gnd to pins 1 & 5. Use variable resistor at pin 3 to set contrast. Pins 7 to 14 are the data pins,, used to send/rec data. Pin 6 is of enable; every time when you write to lcd you should have to give high to low, to this pin. pin 4 is register select pin use to give commands like clear, home etc. In this tutorial i will interface lcd in 4-bit instead of 8-bit, so we only required four data pins. Code: Lets write a code that will display the motor status and its direction; it will be fun!!!! Requirements: Design a motor controller circuit using l298 and display its status on lcd. LCD is connected to portb and motor controller circuit is at portd. Required two switches to change motor direction; i...
This is a Electronic Extended Play Circuit Diagram. A single op amp-one of four contained in the popular LM324-is operating in a variable pulse width, free-running square wave oscillator circuit, with its timed output driving two transistors that control the on/ off cycle of the tape-drive motor. The Oscillator` s positive feedback path holds the secret to the successful operation of the variable on/ off timing signal. Electronic Extended Play Circuit Diagram The two diodes and pulse width potentiometer R8 allows the setting of the on and off time, without affecting the oscillator`s operating frequency. One diode allows only the discharge current to flow through it and the section of R8 that it`s connected to. The other diode, and its portion of R8, sets the charge time for the timing capacitor, C3. Since the recorder`s speed is controlled by the precise off/on timing of the oscillator, a simple voltage-regulator circuit (Ql, R3, and D4) is included. Connecting the spe...
LA4145 an IC with SIL-9 package and manufactered by SANYO. This ic has miraculous equation with LA4146 and LA4147, so if you do not have the IC LA4145 but you have IC LA4146 or LA4147 , you still can make the above amplifier circuit. The circuit includes circuit of classes on low power because it has low output is 1W with 8 ohm impedance. Technical information : Min. Voltage = 6 Volts Max. Voltage= 12 Volts P. Out = 1 Watt RL = 8 Ohm Ft = 40Hz - 17 Khz Icco = 10 mA You can use to : Tuner/ Radio Mini VCD/DVD Walkman Ipod/Ipad Mp3, Mp4 player etc.
ELECTRICAL NOISE AND INTERFERENCE : Definition of electrical noise Noise, or interference, can be defined as undesirable electrical signals, which distort or interfere with an original (or desired) signal. Noise could be transient (temporary) or constant. Unpredictable transient noise is caused, for example, by lightning. Constant noise can be due to the predictable 50 or 60 Hz AC 'hum' from power circuits or harmonic multiples of power frequency close to the data communications cable. This unpredictability makes the design of a data communications system quite challenging. Noise can be generated from within the system itself (internal noise) or from an outside source (external noise). Examples of these types of noise are : Internal noise Thermal noise (due to electron movement within the electrical circuits) Imperfections (in the electrical design). Shot noise is generated by individual electrons "jumping" across some sort of barrier potential as they travel ...