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Simple Frequency Meter

A retriggerable monostable multivibrator and a D flip-flop can form a simple, yet reliable frequency comparator that compares an input frequency with a predetermined reference. To determine whether an input frequency (f) falls between two known frequencies, f1 and f2, two one-shot/flip-flip combinations are used, as shown. Here both the one-shot and the flip-flop ICs are wired for positive-edge triggering. Each input pulse causes the monostable output to go high for the period of its preset timing interval. The flip-flop is triggered simultaneously, but its output is determined by the state of its D input at the time of trigger threshold. If the period of the input frequency is shorter than the preset timing of the monostable, a constant high level will be present at the D input, forcing the flip-flop’s Q output to remain high. If the input frequency period becomes greater than that of the monostable, the flip-flop’s Q output will go low. VR1, VR2, and C1, C2 determine the value of...

Introduce Lenovo Debuts 5 Inch Vibe X Smartphone

Introduce Lenovo Debuts 5-Inch Vibe X Smartphone . Lenovo unveiled its new Vibe X, a fairly clear-cut smartphone, at IFA Berlin on Thursday. The 5-inch apparatus arrives with a 1,080p IPS display, a quad-core, 1.5GHz processor, a 13-megapixel camera (coupled with an oddly powerful 5-megapixel one on the front), 2GB of recollection and 16GB of storage. The specs are admirable, but they aren't the best out there. although, add in the premium polycarbonate body — which is just 6.9 millimeters thick and weighs about a quarter of a pound — and Vibe X becomes a solid lightweight competitor in the crowded 5-inch Android arena. On the programs edge, just like most of its new brethren, it sprints Android 4.2. The Vibe X will never reach European or the U.S. coastlines, we've been notified. Price and release designated day are not yet available.

Capacitor Motor

Single phase capacitor motors are widely used in household a ppliances such as water pump , washing machine, freezer, air condit ioning . Simple construction with small resources and working with electricity supply voltage 220 V, therefore ma king the capacitor motor is widely used in household appliances. Stator winding consists of the main winding terminals U1-U2 notation, with the notation and auxiliary winding terminals Z1-Z2-mesh nets connected to the terminals L1 and U1, and the neutral wire connected to the terminal N U2. Capacitors work function to the main winding phase angle difference with the auxiliary winding approaching 90 ° . Setting the direction of motor rotation can be done with a capacitor (see figure): • To produce rotation to the left (counterclockwise) working capacitor CB connected to the terminals U1 Z1 and Z2 and the terminal is coupled with the terminal. • Round to the right (clockwise) a capacitor connected to the terminal work Z1 and Z2 terminals U1 and U1...

TBA820 low power audio amplifier

At this time amplifier circuit based on IC KA2201, TBA820M, LM820M, and U820. You can use all ic is the series under the scheme. This amplifier circuit has a very small output power or low at 2W. Required supply voltage from 3 volts to a maximum of 16 volts. Below is a scheme of this power amplifier Part List R1 = 100K R2 = 120R R3 = 100R C1 = 100nF C2 = 100uF C3 = 470uF C4 = 220pF C5 = 47uF C6 = 100uF IC = KA2201 , LM820M , TBA820M , U820M

LIGHTNING ARRESTER

Electronic Doorbell with Counter Circuit Diagram

This circuit is a doorbell with counter , that means it counts how many times the bell is triggered . It uses a chip synthesizer sound, the HT -2811 ms nothing prevents you from using another device sound generator . The HT -2811 reproduces the sound of a " ding-dong" doorbell . Besides this ic , the circuit includes a CMOS 4026 and Display Driver IC which counts the total number of visitors .  Electronic Doorbell with Counter Circuit Diagram

Build a Cuckoo Sound Generator Circuit Schematic

This circuit generates a two-tone effect very much alike the cuckoo song. It can be used for door-bells or other purposes thanks to a built-in audio amplifier and loudspeaker. Used as a sound effect generator it can be connected to external amplifiers, tape recorders etc. In this case, the built-in audio amplifier and loudspeaker may be omitted and the output taken across C8 and ground. There are two options: free running, when SW1 is left open, and one-shot, when SW1 is closed. In this case a two-tone cuckoo song will be generated at each P1 pressing. Cuckoo Sound Generator Circuit diagram: Parts: R1,R5___________1K 1/4W Resistors R2_____________50K 1/2W Trimmer Cermet R3______________8K2 1/4W Resistor R4_____________82K 1/4W Resistor R6______________1M 1/4W Resistor R7,R17,R20,R21_22K 1/4W Resistors R8,R10,R11,R19_10K 1/4W Resistors R9____________150K 1/4W Resistor R12_____________4K7 1/4W Resistor R13___________100K 1/4W Resistor R14___________220R 1/4W Resistor R15,R22________20K 1...

Mobile Phone Detector

This electroinc Circuit Project of  Mobile phone detector circuit can sense the presence of an activated mobile cell phone from a distance of one and-a-half meters. If a RF signal is detected the cell phone detector circuit will inform you using a sound alarm (beep sound ) and a blinking LED . In this type of circuit (that use high frequency 0.9-3Ghz ) you can not use an LC circuit for frequency tuning. Mobile Phone Detector Circuit Diagram: The circuit uses a 0.22μF disk capacitor (C3) to according the RF circuit to ensure the capability of the circuit to capture the mobile phone signal .This cellular phone detector can detect any activity of a mobile phone : incoming or outgoing SMS , video transmission or voice transmission . The C3 capacitor must have leads length of 18 mm with 8 mm spacing between leads to obtain the desired frequency .  This small disk capacitor acts as a small gigahertz loop antenna to collect the RF signals  . The CA3130 operational amplifier IC i...

Single Transistor Relay Toggle

The circuit below requires a double pole, double throw relay in conjunction with a single transistor to allow toggling the relay with a momentary push button. One set of relay contacts is used to control the load, while the other is used to provide feedback to keep the relay activated or deactivated. Several push buttons can be wired in parallel to allow toggling the relay from different locations. In the deactivated state, the relay contacts are arranged so the 1000 uF capacitor will charge to about 2.7 volts. When the switch is closed, the capacitor voltage is applied to the transistor base through a 560 resistor causing the transistor to turn on and activate the relay. In the activated state, the relay contacts are arranged so the 3.3K resistor and 560 ohm resistor provide a continous current to the transistor base maintaining the activated state. While in the activated state, the capacitor is allowed to discharge to zero through the 1K resistor. When the switch is again closed, the...

parts of the transformer

Alembic Stratoblaster Point to Point Layout

Courtesy Light Circuit

15 seconds delayed switch-off A good idea for bedroom lamps This circuit is intended to let the user turn off a lamp by means of a switch placed far from bed, allowing him enough time to lie down before the lamp really switches off. Obviously, users will be able to find different applications for this circuit in order to suit their needs. Circuit diagram : Courtesy Light Circuit diagram Due to the low current drawing, the circuit can be supplied from 220Vac mains without a transformer. Supply voltage is reduced to 10Vdc by means of C1 reactance, a two diode rectifier cell D1 & D2 and Zener diode D3. IC1 is a CMos 555 timer wired as a monostable, providing 15 seconds on-time set by R3 & C4. When SW1 is closed, IC1 output (pin 3) is permanently on, driving Triac D4 which in turn feeds the lamp. Opening SW1 operates the monostable and, after 15 seconds, pin 3 of IC1 goes low switching off the lamp. Notes: The circuit is wired permanently to the mains supply but current d...

Requirement definition specification

requirement definition A statement in natural language plus diagrams of the services the system provides and its operatinoal constraints. Written for customers. requirement specification A structured document setting out detailed descriptions of the system services software specification A detailed software description which can serve as a basis for a design or implementation. Written for developers Requirement readers

TDA7594 Audio Amplifier 50W

TDA7594 general description:      The Type IC TDA7294 from SGS-Thomson is an integrated a.f. amplifier intended for use in all sorts of hi-f application. According to the manufacturer's data sheets, chip can deliver outputs of up to 100 watt. Considering other properties, such as low noise, low distortion and reliable short-circuit and thermal protection circuits as well, the chip is indeed an interesting one. Moreover, with peak supply voltages of ±40 V and a load impedance of 4 ohm, the maximum dissipation of the IC TDA7294 will easily be exceeded. For these reasons, the supply in the present amplifier has been kept down to a safe ±30 V. At these voltages, the chip delivers, without any difficulty, 50 W into an 8 ohm load and 80 W into a 4 ohm load. These are still very respectable figures, particularly in view of the reasonable IC price. The circuit diagram of the amplifier in shows that the IC TDA7294 needs only a small number of external components. The input signal ...

Simple 8 Random Flashing LEDs

This project flashes eight LEDs in an apparently random manner. It uses a 4060 combined counter and display driver IC which is designed for driving 7-segment LED displays.  Circuit diagram : Simple 8 Random Flashing LEDs The sequence is not really random because seven of the LEDs would normally be the display segments, the eighth LED is driven by an output that is normally used for driving further counters. The table below shows the sequence for the LEDs. You can use less than eight LEDs if you wish and the table may help you decide which ones to use for your purpose.

Make it a practice to turn off the lights in your room Tips To Save Energy

 Make it a practice to turn off the lights in your room - Tips To Save Energy Lots of people today leave their bedrooms without turning the lights off. Although lights do not consume much electricity, lots of energy would be wasted if you constantly left them turned on for the most parts of the day, even if you are not inside the room. Thus, make it a practice to turn off the lights, so that you can save energy.  Make it a practice to turn off the lights in your room - Tips To Save Energy

LTC2990 System Monitoring IC

Using LTC2990 integrated circuit you can design a very simple monitoring system to monitor system temperatures, voltages and currents. Through the I2C serial interface, the device can be configured to measure many combinations of internal temperature, remote temperature, remote voltage, remote current and internal VCC. The internal 10ppm/°C reference minimizes the number of supporting components and area required. Selectable address and configurable functionality give the LTC2990 flexibility to be incorporated in various systems needing temperature, voltage or current data. Bellow you can see some ideas how to use the LTC2990 I2C Temperature, Voltage and Current Monitor Ic in your electronic projects . You can use LTC2900 IC for electronic projects like :motor protection , fan temperature alarm , battery monitoring , liquid level sensing and many other projects .

20W Audio Power Amplifier Circuit

Description: The NTE7011 is an integrated circuit in a 12−Lead SIP type package designed for use as a BTL power  amplifier with built−in headphone amp for portable stereo applications. Typical applications include  portable component stereos, car stereo, radio cassette recorders, and TV sound multiplex output. Features:  Low Quiescent Current, Low Distortion, Low Noise, High Output Power  Wide Supply Voltage range: VCC = 6 to 26V  Built−In Muting Circuit  Built−In Protection Circuits: Temperature, Surge, Overcurrent  Built−In Headphone Amplifier Circuit

Charge Pump LED Driver Using CAT3649

A very simple LED driver electronic project can be designed using the CAT3649 high efficiency quad mode R fractional charge pump IC that can drive up to six LEDs. The inclusion of a 1.33x fractional charge pump mode increases the device efficiency by up to 10% over traditional 1.5x charge pumps with no added external capacitors.Low noise input ripple is achieved by operating at a constant switching frequency which allows the use of small external ceramic capacitors. The multi−fractional charge pump supports a wide range of input voltages from 2.4 V to 5.5 V. The LED current can be adjusted in different ways. The full−scale LED current is set to 25 mA once the device is enabled. Analog dimming in 32 linear steps is achieved via a 1−wire pulse−dimming input (ADIM) Further adjustment of the LED current can be done by applying a pulse width modulation (PWM) signal on the PWM input.The CAT3649 can be shut down by holding the ADIM or PWM input in a logic low condition for greater than 30 ms....