IC555 can be used to generate PAM with one NPN transistor connected at output. The chip is configured in astable mode to generate pulse train to get samples of information (audio) signal. Its frequency should be at least twice that of audio signal. Usually it is 8 KHz (because audio signal is up to 3.4 KHz) but for better quality here I am keeping it 32 KHz. This pulse train output is fed to base of NPN transistor. The collector of transistor is coupled with low frequency audio (information) signal through positive clamper made up of capacitor C1 and diode D1.
Simple TRIAC Controlled Ceiling Fan
Conventional Ceiling fans operate with voltage divider circuit. Alternatively Ceiling fans can even be operated with Silicon Controlled Rectifiers TRIAC, and 555 timer circuits. This circuit is very cheap in its build. Circuit Diagram Tab 1 shows the TRIAC ceiling fan circuit while circuit diagram tab2 details with the power supply. Working The 230V 50Hz supply…
Digital Clock without Microcontroller
Digital clocks normally function by microcontrollers. Here is a circuit for electronic enthusiasts who can make a digital clock without using any expensive controllers, or having no knowledge of microcontrollers or programming. The whole functioning is solely based on simple IC’s. Components used IC 555 (Timer) — one. CD4518 (CMOS dual up counter) — two.…
Transistor Tester Circuit Diagram
This project is a transistor analyzer, suitable for testing both NPN and PNP transistors. Its circuit is simple as compared to other transistor testerswhich is [[wysiwyg_imageupload::]]useful for both technicians and students. It can be easily accumulated on a general purpose PCB. Basic electronic components like resistors, LED’s, diode and NE5555 are used for developing this circuit. Using this circuit, many of the faults can be checked like transistor is in good condition or not, is it opened or shorted, and so on. NE555: As the name suggests, NE 555 is multivibrator IC which is popularly known to work in three modes: astable, monostable and bistable. Also, circuit can work through a battery for a longer duration, without compromising the working abilities or disturbing the normal functioning of the passive components attached.
Water level controller cum indicator circuit diagram
The water level controller cum indicator is common nowadays. It is built using timer NE555, inverter buffer CMOS IC CD4049 and ULN2003.The [[wysiwyg_imageupload::]]components used here have low cost, are easy to build and install on the overhead tank so as to prevent wastage of water. This circuit of this project is simple, economical and versatile. It is used to switch on the motor pump when the level of water falls below the lowest level and turns off the motor when the tank is full. This project has a very simple circuit consisting of 3 probes which are used for automatic fill and cut of the water supply in tank. These are GROUND, HIGH and LOW. The GROUND probe is used for the reference. When the circuit is powered up for the first time the pump should be started automatically if the vessel is empty (or the level is below the required minimum level). As the HIGH level of the probe is reached, the pump must STOP. If the tank/container is already FULL then nothing should happen.
Touch Switch Circuit using 555 Timer
In this project, when power is supplied to the touch switch circuit, the devices connected to it remain ideal as voltage at pin2 is zero. When the switch is turned ON, trigger pin (pin2) receives trigger signal. The output pin (pin 3) receives a high output due to which transistor gets turned ON. Simultaneously relay…
Tone generator Circuit Diagram
The tone generator’s function is to produce different frequency sine wave for each digital word applied to its input. This project allows the computer to sweep [[wysiwyg_imageupload::]]the instrument under test through the desired frequency range. It can be adapted to create a Morse code circuit, by adding a switch to the output. The circuit here is based upon 555 as a free running multivibrator. The project is based on 555 timers, working as a free running oscillator. The frequency or pitch of the tone is set by the resistors and capacitors situated in the left side of the circuit. The capacitor is used to reduce noise or undesired signals for smooth operation of potentiometer.Read more to find out how the circuit is constructed and how it works.
Sound Generation using 555
The task of this circuit is to give a frequency output which lies in the audible range of a human being, i.e in between 20 and 20,000Hz. Sound is generated in this [[wysiwyg_imageupload::]]circuit by using two 555 timer IC’s. The other components required in this project, along with the two ICs are few resistors and capacitors, one diode, 12 Volts DC power supply, and a speaker. In this project both the ICs are wired as astable multivibrator. Both the 555 timers operate at different frequency ranges. IC1 works at a frequency of about 20Hz as a slow astable multivibrator with duty cycle of 50%. IC2 operates at a frequency of 600Hz as a fast astable multivibrator. Keep on reading to find out how the circuit is constructed and how it works.
Led Flasher Circuit
The operation of the LED flasher circuit project is based on 555 timers with few other components. It flashes the LED ON and OFF after regular intervals of [[wysiwyg_imageupload::]]time. It can be used as eye of a toy to find the toys in the dark, in events like wedding ceremonies, birthday parties or any other events to grab the attention. The LED Flasher circuit project here is based on 555 timers. The timer is wired in astable mode which means that its output is a square wave oscillator. The two LEDS are connected in such a way that when one is ON other is OFF and vice versa. Keep on reading to find out how the circuit is constructed and how it works.
Vehicle Indicator Circuit
The circuit depicted in the article can be used as an indicator in vehicles. Here two identical circuits are used one for left and the other for right. This project can [[wysiwyg_imageupload::]]be installed in our vehicles when the indicators are not working. Even in Bi-cycles at the place of inbuilt indicators that works manually.IC555 is the most versatile chip and it is (can be) used in all most every kind of application because of its multifunctionality. As we know it’s on chip multivibrator means with IC555 one can design astable, monostable, bistable multivibrators. Its main applications are to generate timings, clock waveform, generate synchronizing signals, square wave oscillator and many more. Read more to find out how the circuit is designed and how it can be made to work.
Electronic Dice Circuit
It is very simple and easy to construct a project on electronic dice circuit that will display random numbers from 1 to 6 on the 7 segment display. It is based on [[wysiwyg_imageupload::]]IC CD4017 and NE555. This is an alternative device that can be used to replace the traditional dice when playing games such as snake ladder, monopoly etc. While NE555 is a well known multivibrator IC, CD4107 is a medium speed Johnson Counter that works at 10MHz and has 8 decoded ouptuts. The clock pulse is provided by the 555 astable circuit at about 5 KHz for the 4017 counter which contains ten outputs (Q0 to Q9). Each output becomes high when the clock pulses are received by them. As only six outputs (Q0-Q5) are needed so Q6 is connected to reset. Appropriate outputs are connected through the diodes so as to supply the LEDs: for example Q1, Q3 and Q5 are combined for LED 1.
Bi Color LED
This circuit uses Bi-color LED which creates an eye-catching running display effect. This project can be used in the places like borders of animation, pictures, [[wysiwyg_imageupload::]]short word display etc. The bi-color LEDs are similar to uni-color with the difference that there are two LEDs housed in a package. Bi-colour LEDs may have two or three leads depending upon the internal connections. In this circuit five Bi-color LEDs are used. The LEDs first light in green color, from top to bottom and then in red color, from bottom to top. The IC1 provide clock pulses to the input of decade counter IC2. At each clock pulse, IC2 counts from 0 to 9. The first five pulses lights up in green color when they reach the green anodes of the bi-color LED. Similarly, next five pulses lights up in red color when they reach the red color anodes.
555 Timer IC Tester
The NE555 timer IC is 8 pin DIP which performs a number of tasks in electronic circuitry. It is becoming very much popular among hobbyist as there is a huge list of circuits and experiments which can be performed using it. This project helps to test whether a 555 timer IC is properly functional or not.This IC testing circuit can test any of the 555 timer IC. This is done by testing whether it is oscillating or not. By using this tester it can be immediately tested whether the timer is functional or not. It also tells if it is shorted or oscillating. If both the LEDs are flashing, the timer is in good working condition and if both the LEDs are OFF or on solid then it is defective. It can also be used as a trouble shooter in 555 based circuits. In this project the IC is wired in the astable multivibrator mode. When the power is supplied, the LEDs starts flashing which shows IC is in good working condition.
555 Timer As Amplifier
In its most simplistic form an amplifier can be built with a single 555 timer. The project is based on the concept of condenser MIC. The MIC is used as sensors to sense the incoming audio signals and convert them to appropriate electrical signals. In this project, a 200mA of current capability is enough to drive a small speaker, which makes it a good replacement for a low power amplifier. But when more power is needed to allow listening music in a small room then a high power stage needs to be added with it.The function of 555 timer is very much comparable to pulse width modulation (PWM). The value of the component used in the circuit causes 555 to oscillate at approximately 66 KHz. As we know, speaker does not respond to this much high frequency. Instead it responses to the usual CD value of the modulated output and explains the concept of PWM.
2-1 Quiz Buzzer
Quiz games are becoming very popular these days. The main concept behind these games is the use of fastest finger first indicators which are used to test the [[wysiwyg_imageupload::]]reaction time of the contestants. When the players press the button then the designated player’s number is displayed with the use of audio-visual alarm. The project here has a circuit that can be used for 2 players or teams only. It can be used to identify which of the two has first pressed the button and locks out the other on. The project is made up of two 555 timers which are sometimes known as Schmitt trigger as they work in bistable state i.e. produce either a low or a high output. In this circuit when the trigger input is low the output of the circuit becomes high and when the reset input is low the output also becomes low.
Voltage Doubler Circuit Using IC555
Most of this project is circuit used for doubling the voltage uses the principle of charging and discharging the capacitor. The circuit described below is used to [[wysiwyg_imageupload::]]double the input DC power by using IC 555 timer with capacitors and diodes. This circuit is useful when higher voltage level is required from a single lower voltage power supply.This project is based on 555 timer wired in astable mode means it will produce a square wave at a frequency of 2KHz approx with the help of components R1,R2 and C1.When input power is supplied to the circuit an output is produced at PIN3 of IC1. Continue reading to find out how this circuit can be constructed and what connections can be made to make this circuit work efficiently.
Vehicle Indicator
The project illustrated below helps to find out nearby person or vehicle and make them visible to one another. It can be used in various applications for [[wysiwyg_imageupload::]]pedestrians, runners, bicyclists, motorcyclists, vehicles etc.Most of the time during the night when the roads are badly lit the risk of accidents increases. Sometimes it happens that our vehicle breaks down and we need help. In such conditions this reflector can be used which automatically gets turned ON when it receives light from another vehicle passing nearby. The circuit is based on 555 timer IC and uses a NE555 version of it. Keep on reading to find out how the circuit is designed and how it works.
Night Lamp using 555
Ever imagined how the street lights get turned ON automatically in the evening and gets switched OFF in the morning? Is there anyone who comes early morning to turn off these lights? The following circuit can perform this job properly. This project uses the output from a simple light/dark activated circuit known as LDR (Light Dependent Resistor) and drives a relay in its output which can be further coupled to switch on/off an electrical appliance in a household. An appliance can be made dark or light activated by slightly changing the circuit’s configuration. This idea finds numerous applications such as, automatic watering of gardens in evening, automatic night lamp, dark activated siren and so on.
Short Circuit Detector
The short circuit detector described here can be used to detect short circuit condition on a LOAD operating at a maximum voltage of 12V. It is applicable to any portable devices working below 12V. The circuit employs a PNP transistor and a 555 Timer. COMPONENTS: 1. 555 Timer 2. PNP Transistor (2N3906) 3. Relay PNP…
Monostable mode of 555 timer using NAND gate
555 timer IC is commonly used in monostable mode to generate a pulse every time a trigger is given. The project described here uses NAND gate for [[wysiwyg_imageupload::]]monostable operation and thereby avoiding the need of 555 timer.The circuit in the project uses IC 7400, which has four inbuilt NAND gates. Here we have used the first and second NAND gate of the IC 7400. Suppose, initially the trigger input T is High at a logic level “1” so that the output from first gate (U1) is Low at logic level “0”. The resistor, R will cause the capacitor, C to charge or discharge. The output from the second NAND gate (U2), which is connected as an inverting NOT gate is also fed back to the input of U1,which is at logic level “1”. Since both junction V1 and the output of U1 are both at logic “0” no current flows in the capacitor C and this results in the circuit being Stable and will remain in this state until the trigger input T changes.