Vacuum Tubes Valves
Musical & effects
Yagi Uda Antennas
Metal Detector Circuits
Liquid Sensing Circuits
Light Sensing Circuits
Voltage Detector Circuits
Air-Gas Detection Circuits
Human Sensing Circuits
RF & Radiation
Optical Sensing Circuits
Free Energy Circuits
AC to DC & DC to DC
Solar Cell Circuits
Micro Power Circuits
Switching Power Supplies
Light Laser LED
Digital to Analog
Analog to Digital
Data Bus Circuits
Voltage to Pulse
Current to Voltage
Frequency to Voltage
RF Converter Circuits
Sine to Square Wave
Voltage to Current
voltage to frequency
Period to Voltage
Video Wall circuits
TV Video Circuits
Motor Control Circuits
8051 / 8052
PCB CAD Software
Car bike Circuits
555 Timer Circuits
Remote Control Toy
H Bridge Circuit
Interconnection & Timing
Digital Signal Integrity
Digital & Bipolars
Sensors & Detectors
Regulated Power Supply
4 Band Resistor
5 Band resistor
6 Band resistor
555 Timer Circuits
555 Timer Circuits
555 Negative Voltage Power Supply Circuit
555 Negative Voltage Power Supply Circuit A negative supply can be generated by a ""Charge-Pump"" circuit created with a 555, diodes and..
555 Timer Time Delay Circuit
555 Timer Time Delay Circuit LEDs indicate at a glance what the status of the circuit is at any given moment. Once the reset switch, SW2, makes..
555 Timer With Audio Alarm Circuit
555 Timer With Audio Alarm Circuit Here is a very simple circuit for electronic timer with audio alarm. With the help of this circuit, audio..
555 Variable Frequency Square Wave Generator
555 Variable Frequency Square Wave Generator This simple 555 Variable Frequency Square Wave Generator produces a variable frequency output of..
Accurate 50Hz Oscillator Circuit Using 555 And 7490
Accurate 50Hz Oscillator Circuit Using 555 And 7490 This circuit is a getting a 50Hz pulse. It comprises a 555 timer and two 7490 divide-by-ten..
This is a very simple -5V supply using one 555, useful for analog blocks using FET Opamps using low power. This circuit came up when i had to design limited by inventory. It worked well for its need. It converts Positive Five Volts to Negative Five Volts to create a dual supply. This +5 to -5 using a 555 Astable Multivibrator. is not a high efficie
Code Practice Oscillator Using 555 Timer
This simple code practice oscillator project for beginners to Continuous Wave Morse Code uses a 555 timer to generate a dit or dah sound when the key is pressed
555 Oscillator Tutorial (Astable Multivibrator)
Electronics Tutorial about the 555 Oscillator and How the 555 Oscillator can be used as a 555 Astable Oscillator Circuit to Generate Square Wave Waveforms..
Water Level Alarm Circuit Using 555 Timer
The aim of this project is to build a water level detecting alarm circuit with simple and low cost hardware. Here we use 555 timer circuit in astable mode
555 timer reverse polarity 2
Originally Posted by CDRIVE Thanks for clarifying that. Since you have a dual (+-) supply a SPDT relay will suffice. Do you want a solid state..
555 timer as a voltage to frequency converter
Hi All, I am currently working on a project that requires a 0-10V DC supply to be converted into a linear fequency range - square wave. for instance..
NE555 damaged by ultrasonic operation
Hello: First of all I must start with the classic ""I`m new to this forum so excuse if this post is in the wrong section / this was already..
Triggering a 555 with another
Can anybody tell me if the output of a monostable 555 timer circuit can be used to trigger another similar timer circuit. I have shown my idea with a..
555 audio oscillator Analog Integrated Circuits
The 555 integrated circuit is a general-purpose timer useful for a variety of functions. In this experiment, we explore its use as an astable multivibrator, or oscillator. Connected to a capacitor and two resistors as shown, it will oscillate freely, driving the LEDs on and off with a square-wave output voltage. This circuit works on the princip
555 Electronic Metronome Circuit
I have assembled the metronome circuit several times and it did not work. Two 555 manufacturers websites (ON Semiconductor and National Semiconductor) propose circuits that differ from yours in that pins 2/6/7 are not joined together but there is a resistor Ra between +Vcc and pin 7, a resistor Rb between pin 7 and pin 6 (= pin 2
1 Hz Pulse Frequency Generator with 555
A 1Hz pulse/frequency generator using the popular timer IC 555 which is wired as an Astable Multivibrator. The output pulses can be indicated visually by the LED. An Astable Multivibrator, often called a free-running Multivibrator, is a rectangular-wave generating circuit. Unlike the Monostable Multivibrator, this circuit does not require
Time Delay Relay Circuit with 555
This time delay relay circuit is built with IC NE/SE555, produced by Intersil which contains a precision timer. Stability to temperature variations is 0.00..
555 DC Voltage Doubler Circuit
This dc voltage doubler circuit produces a voltage that is twice its voltage supply. This is useful when a higher voltage level is needed out of a single lower voltage power supply. Since the current consumption levels are low in such cases, the circuit can be built with minimal resources. The electronic circuit is basically a square wave generato
LED Driver Circuit with 555 Timer
This simple LED driver circuit allows us to drive up to seven LEDs by using a single NiMH (Nickel Metal Hydride) AA cell. The circuit produces voltage puls..
555 Low Voltage Operation
I had heard some stories in the past concerning how poorly the 555 ran below Vcc = 5V, so I embarked on an endeavor to see if I could improve operation. Th..
555 Duty Cycle Control
Here is a simple oscillator circuit that varies the duty cycle over a wide range without affecting the frequency. It is a variation of the simple 555 astab..
Inverted 555 Timer Circuit
Whenever I use the 555 timer, it seems that the output polarity is invariably incorrect, and the way the 555 functions, it normally cannot generate a duty cycle of less than 50% ” 90% yes, 10% NO! This inverted 555 circuit generates duty cycles of less than 50%. Everything works the same except for the polarity. Why not simply invert the...
Wide Frequency Range 555 VCO
The 555 frequency can be varied via adjusting the voltage at pin 5. However, the range and linearity of frequency adjustment is very limited. This is a way..
Quirky 555 Timer Reset Function
How many have had legitimate problems with the 555 timer? Let me guessit involved the reset line, did it not? We all know that pin 4 must be set high befo..
Door Ajar Light Flasher
A magnet is placed on the door and a magnetic reed switch on the door casing so when the door is closed the circuit is disabled. When the door is open, the..
555 Christmas Lights Project
This is different than the standard 555 oscillator circuit in that the LED is placed in the capacitor reset line (pin 7). By doing so, overall current is reduced and the high peak LED current does not flow out of the battery. Since the forward drop of the LED can interfere with the reset threshold voltage when the battery voltage is low, the capac
555 Voltage Doubler Relay Driver
These novel relay driver circuits have the ability to pick up a relay with a coil voltage rating equal to double Vcc. After pickup, the relay armature is h..
555 Touch Sensor Switch Circuit
This kind of sensor switch is suitable for making touch operated bells, buzzers of small toys which operate for a small time and then switch off automatically. The input impedance of the trigger is very high and the touch sensor switch can be triggered by the voltage induced in the human body. The relay is a 12 V DC relay operating at currents les
555 LED Flasher Circuit
This is a small size led flasher built with the 555 timer IC that is powered from 2 x 1. 5V batteries. The circuit can be used as a flashing metronome, dark room timer, memo-reminder or other similar applications. In figure 1 the LED will be ON for a short period of time and OFF for a longer period. The duty cycle can be reversed if the LED is conn
220V Flashing Lamp Circuit with 555
This 220V mains operated solid state flashing lamp circuit uses a 555 timer IC to control the ON and OFF times of a triac which controls power to the load
Light Activated Relay with 555 Circuit
This light activated relay circuit presented here uses the 555 timer IC and a light dependent resistor or LDR to form a light sensitive relay in an intruder alarm system or for switching on a lamp at Sun set and off at Sun rise. Potentiometer R1 value must be chosen and then adjusted that under normal conditions when the light is falling on the LD
Temperature Controller with 555 Circuit
Build a temperature controller circuit with the 555 IC together with a thermistor resistor divider. The advantage is that a well regulated power supply is not needed. The dividing network consists of adjustable resistor R3, thermistor R4 and R5. When the thermistor temperature is below a set value the voltage at pin 2 of the 555 drops belo
RC Model Toy Circuits
H Bridge 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