Rongge

The circuit consists of power supply and control sections. The power supply section is built around transformer X1, bridge rectifier BR1 and filter capacitor C1. The 50Hz, 230V AC mains is stepped down by transformer X1 to deliver a secondary output of 9V, 300 mA. The transformer output is rectified by the bridge rectifier and filtered by capacitor C1. Fan and Air-Conditioner Control Switch circuit Diagram When the mains is switched on for the first time, pin 3 of IC CD4017 (IC1) goes high and relay RL1 energises to switch on the fan. When mains is briefly switched off using S1 and then switched on, the power to IC1 is maintained by the charge on capacitor C1. At the same time, there is a trigger pulse on the clock input (pin 14) of IC1, which advances the decade counter and relay RL2 energises to switch-on the air-conditioner. Both the air-conditioner and the fan will be turned off if the switch is in the ‘off’ position. Assemble the circuit on a general-purpose PCB and enclose in a s...

Telephone line Based Audio Muting and Light-On Circuit . Very often when enjoying music or watching TV at high audio level, we may not be able to hear a telephone ring and thus miss an important incoming phone call. To overcome this situation, the circuit presented here can be used. The circuit would automatically light a bulb on arrival of a telephone ring and simultaneously mute the music system/TV audio for the duration the telephone handset is off-hook. Lighting of the bulb would not only indicate an incoming call but also help in locating the telephone during darkness. . Telephone line Based Audio Muting and Light-On Circuit diagram :   Telephone line Based Audio Muting and Light-On Circuit Diagram  . On arrival of a ring, or when the handset is off-hook, the inbuilt transistor of IC1 (opto-coupler) conducts and capacitor C1 gets charged and, in turn, transistor T1 gets forward biased. As a result, transistor T1 conducts, causing energisation of relays RL1, RL2, and RL3...

Plastic, a new card that allows you to store credit cards, debit cards, gift cards and frequent shopper in one. It has an e-ink screen and has security chip. Your wallet will be made once you know Plastic diet, a device that would replace most secured credit cards, debit cards, gift cards and frequent customer. The device is a card that is linked to an application on your phone (via Bluetooth). Plastic has the ability to store up to 20 cards and the application keeps a history of transactions. Does this sound familiar? This is because you probably remember the product called Coin which was introduced in 2013 or 2010 presented in 2.0 Card Like Plastc, these products attempt to store the information of different cards to choose which you want to use each time you want to use. The difference between Plastic and other cards is that Plastic can display bar-codes, frequent shopper cards or gift cards and all information can be erased remotely if it has been lost or stolen. Plastic has a scre...

Controlling temperature has been a prime objective in various applications including refrigerators, air conditioners, air coolers, heaters, industrial temperature conditioning and so on. Temperature controllers vary in their complexities and algorithms. Some of these use simple control techniques like simple on-off control while others use complex Proportional Integral Derivative (PID) or fuzzy logic algorithms. In this project Shawon Shahryiar discusses about a simple control algorithm and utilize it intelligently unlike analogue controllers. Here are the features of this controller: Audio-visual setup for setting temperature limits. Fault detection and evasive action. Temperature monitoring and display. Audio-visual warning. System status. Settable time frame. Data retention with internal EEPROM memory. [ ]

Advantages, disadvantages and application of FET over BJT Advantages 1.        FET gas high input impedance of several mega ohms. 2.        The noise produced by a FET is less than that produced by a BJT. 3.        FETs are less effect by radiation compared to BJT. 4.        FET has no offset voltage at zero drain current and hence it forms an excellent signal chopper. 5.        FETs are voltage controlled devices. 6.        FETs have better thermal stability. 7.        In the integrated circuit form FET is simpler to fabricate and it occupies less – space. Disadvantages FETs have a drawback of smaller gain bandwidth product compared to BJT. Applications The high input impedance and low output impedance and low noise level make FET for superior of the bipolar transistor. Some of t...

      The P-N junction diode is appeared in the year 1950. It is the most essential and the basic building block of the electronic device. The PN junction diode is a two terminal device, which is formed when one side of the PN junction diode is made with p-type and doped with the N-type material. The PN-junction is the root for semiconductor diodes. The various electronic components like BJTs, JFETs, MOSFETs ( metal–oxide–semiconductor FET ), LEDs and analog or digital ICs all supports semiconductor technology. The main function of the semiconductor diode is, it facilitates the electrons to flow totally in one direction across it. Finally, it acts as a rectifier. This article gives a brief information about the PN junction diode, PN junction diode in forward bias and reverse bias and the VI characteristics of PN junction diode What is a PN Junction Diode? There are three possible  biasing  conditions and two operating regions for the typical PN-Junctio...

LED BACKLIGHTING SOLUTION WITH LM3430 and LM3432 ELECTRONIC DIAGRAM The LM3432 is a 6-channel high voltage current regulator which provides a simple solution for LED backlighting applicationsand the LM3430 is a companion device to supply high voltage required to drive serially connected LED strings. The LM3430 and the LM3432 provide a complete solution to most HB-WLED backlighting applications for notebook and PC monitor. In this application note, a typical example for a solution to drive six strings of twelve LEDs in series running at 20mA per string is described in details.

Pointers and Scales in Measuring Instruments Instrument scales and pointers may be considered together in two classes: (A)     Those intended for reading quickly (in the case of switch board instruments at a distance), and (B)      Those intended for close accurate reading for portable instruments. Pointers: The shape and size of the pointers depends upon the type of instrument. The weight and inertia of pointer must be reduced so as to reduce the load on the bearing and to avoid necessity of damping torque. The pointer motion is usually limited by buffer stops little more than the scale. These stops are constructed as very light springs so that the pointer is not bent when it strikes them sharply on a sudden overload or reversal of the operating current. fig 1. Pointer The pointers for switch board and panel instruments should be so that the position of the pointer is conspicuous. The pointers are usually broad or carry broad targets at their ends. Al...

iPhone 6 concept shows thinner handset with touch-sensitive home button and 12MP camera Created by Arthur Reis, a budding designer who aspires to join the ranks of Jony Ive and Shin Nishibori someday, 3D renderings of the iPhone 6 imagine a handset that looks largely identical to iPhone 5 (think: anodised aluminium casing with chamfered edges), but an impressive 20 per cent slimmer at just 6.1mm thick. The handset also features a 12-megapixel camera with an ‘iSight Pro’ sensor boasting an f/1.8 aperture and a ‘Magic TrackPad’ that replaces the physical home button with a touch-sensitive equivalent. As far as we’re concerned, this is one of the best iPhone concepts we’ve seen, principally because it doesn’t go crazy on novel or unrealistic features as most concepts do. Apple is always trying to make its handsets slimmer, so a more slender iPhone is within the realms of possibility. And with Samsung upping the ante with a 13-megapixel camera on the freshly launched Galaxy S4, we can cert...

Nowadays, just about every house has an outside lamp with a motion sensor. Such a device eliminates the need to feel your way to the front door, and it apparently also scares away intruders. The only problem is that free-running dogs and cats in the neighborhood have little regard for such lamps and continue to deposit their excrement in the garden, once they have found a habitual location there for this purpose. This gave rise to the idea of connecting a sort of siren in parallel with the outside lamp to clearly advise dogs and cats that they are not welcome. Naturally, it would be nice to avoid startling the entire neighborhood with this alarm signal. Here we can take advantage of the fact that dogs and cats have a significantly better sense of hearing than people. Not only are their ears more sensitive, they can also perceive significantly higher frequencies. With people, the upper limit is around 18 kHz, but dogs and cats can hear frequencies in excess of 20 kHz. We can take advant...

This is a best Frequency/Voltage Converter circuit diagram proportional voltage by the use of a frequency-to-voltage (F/V) converter . Teledyne Semiconductor`s Type TSC9402 is a versatile IC. Not only can it convert voltage into frequency, but also frequency into voltage. It is thus eminently suitable for use in an add-on unit for measuring frequencies with a multimeter.   Best F and V Converter Circuit Diagram Only a few additional components are required for this.. Just one calibration point sets the center of the measuring range (or of that part of the range that is used most frequently). The frequency-proportional direct voltage at the output (pin 12—amp out) contains interference pulses at levels up to 0.7 V. If these have an adverse effect on the multimeter, they can be suppressed with the aid of a simple RC network.  The output voltage, U0, is calculated by: tfo=C/rei(Ci + 12 pF) R2fm Because the internal capacitance often has a greater value than the 12 pF tak...

Apple has announced brand new versions of its iPod Touch, Nano and Shuffle music players The fifth-generation iPod Touch has arrived, alongside the iPhone 5, sporting a 4-inch multitouch screen and thinner, lighter body. Measuring 6.1mm thin and weighing 88 grams, expect up to 40 hours of music playback and 8 hours of video. Siri has also made the jump to the new iPod Touch. On the gaming front, the iPod Touch is 'the world's most popular music player... but a lot of people don't realize that it's also the world's most popular videogame player as well,' according to Greg Joswiak, Vice President for iPod, iPhone and iOS Product Marketing. 175,000 games are available on iOS to date and the new Touch will be taking full advantage of them with its new dual-core Apple A5 processor, offering graphics 7x faster than the previous Touch. The camera has also been upgraded to a 5-meg iSight rear-facing HD cam including backside illumination, an f/2.4 aperture and an identi...

Here are two transistors manufactured by Toshiba. 2SC5200 and 2SA1943 transistor pair has been widely applied or used in the amplifier power amplifier because the transistor has a large power, and also not too expensive than other large power transistors. This transistor has the advantage of High breakdown voltage: VCEO = 230 V (min), Suitable for use in 100-W high fidelity audio amplifier's output stage. For more information, please see datasheet below. Maximum Ratings (Tc = 25°C) Electrical Characteristics (Tc = 25°C)