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Meter Counter Circuits
Create a flash-then-steady LED using a 555 timer
The circuit shown flashes the LED briefly (to get your attention) and stays on as long as the power is on ( Fig. 1 ). The venerable 555 timer IC can be put to use in this type of application. The circuit is a standard astable multivibrator with resistors RA, RB, and the timing capacitor C1. To operate as a free-running astable, the reset pin 4...
555 Timer IC for Square Wave Generator Application
You can start to set your Square Wave Generator up using 555 timer IC through the circuit shown above. Find it match with the pinout of 555 timer IC. The osciloscope is then connected to the output of 555 timer IC in order to view the square wave. From the oscilloscope you can measure the wave frequency and verify it by varying the resistance in
Low-power inverter using LM555 Timer IC
This document describes a basic circuit that can be used to power high impedance, high voltage, low current devices such as EL backlights and fluorescent tubes. This project got its genesis when I needed a simple, yet flexible inverter circuit for an EL backlight, using a 12 volt input. My specific need was to power the backlight for the wildly po
555 How can I make a 15 minute egg timer circuit
To do this, I want to push a button to initiate the timer, which will then light 3 x leds. After each 5 minute segment is up, one of the LEDs should go out. Finally, when 15 mins is up, I want to ring a bell (just once) using a solenoid. Trouble is - I don`t know where to start! My background in more in computer programming - so I understand the...
digital logic purpose of diode in this 555 timer application
Make a 555 timer base circuit such that O/P pin of 555 is held LOW by default at power on, and the I/P pin is held initially at HIGH at power on. The main requirement of my circuit is that until I/P pin is held LOW for say 200ms, then only the O/P pin must go HIGH and must remain HIGH as long as I/P pin is held LOW. What will happen if I pull up...
timer Simple Metronome Circuit w/ Linear Pot Control
To get the usual BPM range for music of between 40 and 240 BPM, that corresponds to periods of 1500 ms and 200 ms respectively. A BPM of 120 is exactly 500 ms. As it is, the circuit would require an R4 of 14. 5 Mohm to yield a period of 500 ms (120 BPM). I need the value to be exactly 5K (10K pot in the center position). Here`s another version.
Driving 72 leds with 555 timer
Make a circuit with a 555 timer to run 72 LEDs all at the same time. I have already made a circuit, but am not sure If it will work safe and long or not. I am putting the picture of the circuit and I want anybody who can help to look at it and see if it needs some extra components. Please add them on the circuit or explain instructions to add.
ac What is the output voltage of this 555 timer high voltage circuit
Calculated the output of the transformer to be 125 times (1000 / 8) higher than input. Since 12v is given as input, output should be 1500v (not sure about this)
microcontroller PIR sensor triggered by itself when using timer works without timer
A PIR sensor is triggered by itself when using a timer to wait 2 seconds after the sensor is triggered. Without using the timer to wait the sensor works as expected. I have a PIR sensor connected to an ATMega328p. The PIR sensor has three pins; VCC, GND and AL. The AL pin uses open collector to show that motion is detected. What I have done is th
transistors IR Emitter/Detector with 555 timer alarm
This circuit detects when a tube is empty and pulses a piezo buzzer in. 5 second intervals. I have it working with 5v on a breadboard, but I need to move it to 12v from a wall wart. Secondly, with 12v R1 should be 220 1W, but I want to stick with 1/4W resistors, maybe 510. Is that possible I realize that will bring down the 50ma current to...
555 and 556 Timer Circuits
The 8-pin 555 timer must be one of the most useful ICs ever made and it is used in many projects. With just a few external components it can be used to build many circuits, not all of them involve timing! A popular version is the NE555 and this is suitable in most cases where a `555 timer` is specified. The 556 is a dual version of the 555 housed
Adjustable 1-10 Minute Timer Project
The circuit starts timing when switched on. The green LED lights to show that timing is in progress. When the time period is over the green LED turns off, the red LED turns on and the bleeper sounds. The time period is set by adjusting the variable resistor. It can be adjusted from 1 to 10 minutes (approximately) with the parts shown in the diagra
A 555 TIMER LED FLASHER CIRCUIT
An astable multivibrator, often called a free running multivibrator, is a rectangular wave generating circuit. The circuit doesnt need any triggering. The timing of the circuit is determined by the resistors and the capacitors used in it. The details of the astable multivibrator are: Pin1 is grounded; Pins 4 and 8 are shorted, Pin 3 gives the timi
Advanced appliance timer
This project introduces important type of transducer, an optical coupler. An optical coupler together with a square wave generator and counters can be used to construct a timer for appliances. That is, an appliance can be turned on at a desired time for a specific time interval, Figure 1 shows a block diagram of such a timer. As shown in Figure 1,
Mains operated Log-Interval Timer circuit
Off timer with alarm with description
Off timer with alarm is a simple project used to indicate time off employs 4 transistor,.circuit diagram with parts list and description of off timer with alarm.various alarm project.
Programmable timer for appliance
Programmable timer for appliance circuit is advanced timer appliance is controlled by timer circuit from 8 sec. to 2 hour.circuit diagram of programmable timer for appliance .
Programmable Timer of timer circuit
Programmable Timer in this website is very simple made from only 2 iC of wide range circuit and description of programmable timer various timer project.
The Universal Timer with description
Universal Timer is a most versatile timer project wide range of 1/10th second to 100s hour time period circuit diagram with description of universal timer various timer circuit .
Timer IC tester LM555 tester
The IC tester in this web site is specially designed for the timer IC LM555. this circuit is used for testing timer IC. circuit diagram and technique of various project .
Timer with musical alarm
Here timer with musical alarm is a electronics timer project using CD4060.delaying from 1 minute to 2 hour.circuit diagram of timer with musical alarm various electronics project.
LED Circuit with Timer 555
This circuit LED reproduces the first LED sequence at this time used by FISA on behalf of Formula single racing. It may perhaps be alive used with slot car sets (such for example HO shin up AFX/Life Like/Tyco sets) or else means of communication controlled cars. IC1, a 555 timer IC, is used as a watch pulse generator. Its output is fed via NAND ga
555 Timer as Monostable Multivibrator
555 timer IC
The 555 timer IC is an integrated circuit (chip) used in a variety of timer, pulse generation and oscillator applications. The part is still in widespread use, thanks to its ease of use, low price and good stability. As of 2003 [update], it is estimated that 1 billion units are manufactured every year.  The IC design was proposed in 1970 by H
Relay Timer with ATmega8 AVR MCU
A simple timer that can be used to turn on/off a load after user specified time. The prototype was developed using xBoard MINI, a low cost easy to use ATmega8 development board. The program was burned to the MCU`s flash memory using eXtreme Burner - AVR Software and Hardware. The Simple Device Timer project designed using ATmega8 AVR MVU.
555 Timer Frequency and Duty Cycle Calculator
Enter values for R1, R2, and C and press the calculate button to solve for positive time interval (T1) and negative time interval (T2). For example, a 10K resistor (R1) and 100K (R2) and 0. 1 uF capacitor will produce output time intervals of 7. 62 mS positive (T1) and 6. 93 mS negative (T2). The frequency will be about 70 Hz. R1 should be...
555 Timer Led Flasher
Class D amp made easy with 555 timer IC
This is a continuation of my previous article regarding class d amp using 555 timer chip. Looking back to several schematics on that article, some of you may wonder why I include another 555 as U2 in the drawing. The main purpose of this U2 is to establish constant frequency trigger on pin 2 of U1 in such a way of maintaining stable PWM carrier fr
Full bridge class d amp using 555 timer
So here is another improvised model circuit that will eliminate the unwanted DC offset voltage from the output that affect the previous one discussed. By the way, all previous circuits that I discussed were intended as low power class d amp source that is adequate to drive head phones via a coupling capacitor. This means DC offset is ignored...
Active crossover network using 555 timer as class d amp
Clap Switch Circuit using NE555 timer IC
Here is one of the interesting 555 timer circuits to trick your friends while studying electronics in schools. Clap switch circuit is the local name of sound controlled flip flops. This sound controlled light can also be used as sound detection sensors. Flip flops are single bit storage elements. NE555 timer IC is the important part of this circuit
Astable Multivibrator using NE 555 timer IC
Astable Multivibrator can be designed by using 555 timer IC, Op Amps and also using transistors. The 555 IC provide accurate time delay from mille seconds to hours. The frequency of oscillation can be controlled manually by simple modification. This is a simple 555 timer circuit project. Astable Multivibrator is simply an oscillator circuit that pr
Frequency Meter Circuits
VU Meter Circuits
Ultrasonic distance finder circuit
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is measured. There are three main categories of distance measurement methods in use: a) By...
Simple Metal detector circuit with CD4030
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to find something potentially valuable, hidden a few centimeters below the soil. So many...
Fully automatic watering circuit for flower pots
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This circuit comes as a solution to this problem. Depending on humidity of the pot at...
Simple deep searching metal detector circuit
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the circuit of this metal detector, it is possible to detect a metal coin in depth of 90 to...
Sub-Harmonic Bass Converter for Electric Guitars
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound, such as filtering or distortion. Instead, a frequency division system produces outputs...
Echo Depth Sounding Sonar for Boats
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the calibration of the rope. This arrangement still exists in some yachts. The big...
100W HiFi Audio Amplifier Circuit
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power supply must be symmetrical so that no electrolytic capacitors are needed at the outlet....
Plant-Pot Water Level Indicator Circuit
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower. The circuit of the device is shown in Figure 2. The water detection is made from the bottom...
Analogue Sound Preasure dB-Meter Circuit
The best human ear can capture sounds from 20Hz to 20KHz. These limits are known to be the broadest that can exist. Normally the normal limits range from 100Hz to about 13KHz and depend on the age and health of the individual. We for our measurements and to have a good accuracy we will get the limits of 20Hz to 20KHz. A sound to be heard does...
Digital Signal Integrity
Interconnection and Timing of Digital Circuits
CMOS Circuits Tutorial