My Circuit

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...

Citing unnamed supply chain sources, as well as what we’re guessing are some better informed sorts within Samsung, the Korea Times claims that the phone will land in February at the Mobile World Congress. The handset is apparently set to hit retailers shortly after in March – just nine months after the release of its predecessor. In news that’s unlikely to surprise anyone on nodding terms with prevailing trends in smartphone upgrades, Samsung’s new kit will purportedly pack a larger five-inch OLED screen – up from the S3’s 4.8-inches - and international 4G LTE support. An unnamed deepthroat said: “Samsung wants to keep its one-year product schedule and the Galaxy S4 will be the first to match that strategy. “The S4 will see some external changes but retain its popular rectangular shape with rounded corner concept.” News of Samsung’s plans comes as it recently announced that the S3 has now sold some 20 million units, making it the company’s fastest-selling phone ever. Source: Ko...

Here is a circuit of mobile phone charger.The main part of the circuit mobile cellphone charger is timer IC NE555, used to charge and monitor the voltage level. IC1 get control voltage to pin 5 by zener diode ZD1­. Threshold pin 6 and trigger pin 2 is supplied with a voltage set by VR1 and VR2 respectively. The trigger pin 2 of IC1 is below 1/3VCC when discharge battery is connected to the circuit as a result flip-flop of IC1 is switched on to take output pin 3 high. The process is reversed when battery is fully charged of charged battery is connected. Here transistor T1 used to enhance the charging current from output pin 3 of IC1. Adjust potentiometer VR1 and VR2 as per require. PARTS LIST Resistors R1 = 390 Ω R2 = 680 Ω R3 = 39 Ω/1W R4 = 27 KΩ R5 = 47 KΩ R6 = 3.3 KΩ R7 = 100 Ω/1W VR1, VR2 = 20 KΩ  Capacitors C1 = 0.001 µF (ceramic disc) C2 = 0.01 µF (ceramic disc) C3 = 4.7 µF/25V (Electrolytic )  Semiconductors IC1 = NE555 timer IC T1 = SL100 or any Medium power general...

Using a mobile phone while driving is dangerous. It is also against the law. However, you can use your mobile phone as a powerful music player with the help of a stereo power amplifier. This does away with the need of a sophisticated in-dash car music system. Most mobile phones have a music player that offers a number of features including preset/manual sound equalisers. They have standard 3.5mm stereo sockets that allow music to be played through standard stereo headphones/sound amplifiers. Nokia 2700 classic is an example.  Mobile Car Stereo Player Circuit Diagram   A car audio amplifier with 3.5mm socket can be designed and simply connected to the mobile phone output via a shielded cable with suitable connectors/jacks (readymade 3.5mm male-to-male connector cable is a good alternative). Fig. 1 shows the circuit of car stereo player. It is built around popular single-chip audio power amplifier TDA1554Q (IC1). The TDA1554Q is an integrated class-B power amplifier in a 17-lea...