My Light Diagram

At New York event, HTC took the wraps of their latest Windows Phone devices. The higher-end HTC 8X comes with a 1.5GHz dual core Snapdragon S4 processor along with a 4.3 inch 720x1280 screen in a 0.39-inch thin form factor. It also features NFC, LTE radio and an 8-megapixel camera along with a dedicated button on the back as a 2 megapixel camera on the front. The HTC 8S comes with a 1GHz CPU and a 4' 800x400 resolution screen with a 5 megapixel camera. Both the HTC 8X and 8S are available in multiple colors such as red, blue and yellow. While they will be available in the US in November, we will try and find out the prices and availability for the Middle East and keep you updated.

Although a simple crystal oscillator may be built from one comparator of an LT1720/LT1721, this will suffer from a number of inherent shortcomings and design problems. Although the LT1720/LT1721 will give the correct logic output when one input is outside the common mode range, additional delays may occur when it is so operated, opening the possibility of spurious operating modes. Therefore, the DC bias voltages at the inputs have to be set near the center of the LT1720/LT1721’s common mode range and a resistor is required to attenuate the feedback to the non-inverting input. Unfortunately, although the output duty cycle for this circuit is roughly 50%, it is affected by resistor tolerances and, to a lesser extent, by comparator offsets and timings. Comparator Based Crystal Oscillator Circuit Diagram If a 50% duty cycle is required, the circuit shown here creates a pair of complementary outputs with a forced 50% duty cycle. Crystals are narrow-band elements, so the feedback to the non...

I have be thinking about a pic microcontroler based voltage regulator for about 3 years now; last week i install a 2.5kva 36V inverter for a consumer of mine... 3 days later he called me that the inverter is not charging the battery well... so i ask him to call me and check the input voltage on the lcd screen when ever their is a mains supply (NEPA).... so he called  confirming that the input voltage was 108volt; we had to design a  2kva automatic voltage regulator from 80V - 260V...     ON 187 V INPUT TEST ON PROTEUS   ON 218V INPUT TEST ON PROTEUS       ON 262V INPUT TEST ON PROTEUS WITH HIGH VOLT G UIDE     RELAY CONFIGURATION   TRANSFORMER CONFIGURATION   A   B              I will upload the code and the pcb soon

Build a 10 LED Bar Dot VU meter circuit based LM3915 . It differs in many respects from other applications on the same chip. The circuit is intended for those who want a VU meter that is connected directly to the output of an power amplifier.  10 LED Bar Dot VU Meter Circuit based LM3915 Circuit Diagram It’s possible to adjust the sensitivity to work with amplifiers that have different output power, you just need to change the value of R1 according to Table 1. In case you did’n find the exact resistor value, then choose the next standard value (for example if you cannot find 33K ohm, then find the 36K ohm), or if you want maximum accuracy you need to put resistors in series or in parallel to achieve the correct value.   You can use various types of LEDs (round or square) to get the visual and aesthetic result you want. The switch S1 will allow you to choose whether VU meter will work as a bar or one by one (dot). In position ON [closed switch], the LED operation is Bar, while ...

There are several methods for controlling the speed of DC motors. One simple method is to add series resistance using a rheostat. As considerable power is consumed in the rheostat, this method is not economical. Another method is to use a series switch that can be closed/opened rapidly. This type of control is termed as chopper control. We’ve described here a PWM-based chopper circuit that smoothly controls the speed of general-purpose DC motors. Fig.1: Block diagram of PWM-based speed controller Fig. 1 shows the block diagram of a basic PWM-based chopper. The circuit shown in Fig. 2 is designed as per this diagram. A dual timer IC (NE556) is used to configure both the astable as well as the monostable multivibrator. Timing components for the astable are chosen to provide a frequency of 546 Hz, while the monostable components are selected to obtain a maximum pulsewidth of 2.42 ms. Diode D1 improves duty factor of the astable oscillator output, whereas D2 acts as a free-wheeling diode. ...

Traffic Light 20 Chanel based on 74LSxx This view of the proposed traffic Light 20 Chane based only on family and 74LSxx IC 555 as clock source. It is a digital logic circuit. To construct the traffic light rangkaian Control requires no programming of microcontrollers. This page features a circuit that has twenty open collector outputs that turn on one at a time in a continuous sequence. The circuit make use of the family 74LSxx TTL integrated logic devices. The circuits are designed to drive light emitting diodes or low current and low voltage incandescent lamps, but can also lead to other charges of 80 milliamps. notes: The low output go in sequence from 1 - 0 and back to 1 -0 At the clock rate of the 555 timer c3 = 1uf to 10uf depending on the rate of change desured R2 (Variable resistor) in use to determine the timer

This voltage monitor is made to display the voltage of 12v battery (for UPS) on LEDs. For this purpose LM3914 is used. The voltage range decided to display is 10v to 13.5v for 12v battery. LM3914 is display driver that can be used in dot  mode or in bar mode; dot mode , with only one led is lit at a time, and in bar mode where it lights leds progressively when the voltage increases. The circuit needs to be powered from the battery being measured and to be able to adjust the lower and upper voltages that light the first and last leds on the led bar. For the 12V battery, the first led in the bar will lit at 10V and the last one at 13.5V , giving 0.35V per led. These thresholds may be set to other values by adjusting two trimmers in the circuit. Calculation and Adjustments: Current flowing per led is controlled by R3 resistor, by applying ohm's law  Ir3 =1.25v/ 4.7kohm =266uA.  Where 1.25v is the minimum voltage required to operate the led. To be able to read the supply vo...

Timers are very useful both for industrial applications and household appliances. Here is a PC-based timer that can be used for controlling the appliances for up to 18 hours. For control, the timer uses a simple program and interface circuit. It is very cost-effective and efficient for those who have a PC at workplace or home. The tolerance is ±1 second. The circuit for interfacing the PC’s parallel port with the load is very simple. It uses only one IC MCT2E, which isolates the PC and the relay driver circuits. The IC prevents the PC from any short circuit that may occur in the relay driver circuit or appliance. The glowing of LED1 indicates that the appliance is turned on. Transistor BC548 is used as the relay driver. The program code is written in ‘C’ language and compiled using ‘Turbo C’ compiler. When the program is run, it prompts the user to input the time duration in seconds or minutes to control the appliance. After entering the required timing, press any key from the keyboard...

Specification : This is stereo amplifier , based on IC TDA4920 , TDA4925 , TDA4930 . Minimum voltage require 9 volts and maximum voltage 13 volts . Maximum power output 2 x 15 Watts with 4 Ohms impedance. Quiescent current 30 mA. See audio circuit scheematic below :

      The project aims to develop a FingerPrint based ATM  Accessing System in which user can make their transactions by fingerprints.  Fingerprint recognition or fingerprint authentication refers to the automated method of verifying a match between two human fingerprints. Fingerprints are one of many forms of biometrics used to identify individuals and verify their identity. A fingerprint sensor is an DSP based electronic device used to capture a digital image of the fingerprint pattern. The captured image is digitally processed to create a biometric template (a collection of extracted features) which is stored and used for matching.       We can use PIC16F877A CMOS FLASH-based 8-bit microcontroller for this project. The microcontroller provides necessary commands for fingerprint searching in the sensor module. In this project, it uses two verification techniques(for more security), the user needs to enter their user name and password, ...