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
New Circuits Page 15
Antenna Input & Audio Lineout Adaptor For Portable Radios
Here is an idea for a simple low-cost adaptor that allows a portable FM radio (or MP3 player with FM tuner) to be connected to an external antenna and to audio equipment such as a hifi system or PC sound card. Portable FM radios and some MP3 players typically provide a 3. 5mm stereo jack socket for the headphone connection, with the shield conducto
1N5401 3.0 AMP Silicon Rectifier
The schematic below shows how the +25V DC and -25V DC are obtained. In order to provide power supply for 2 stereo amplifiers, a power transformer rating of 80VA with 240V/36V centre tapped secondary winding is used. The secondary output of the transformer is rectified by using four 1N5401 diodes toge. The circuit in Fig. 56-11a lights the signal la
Improved vacuum tube models for SPICE
As my principal hobby interest is now photography and I work crazy long hours at Imatest, I won`t have much time to update this article or answer difficult questions. James E. Lanier`s PSPICE Triode Calculator is a promising program for finding tube model parameters. It`s still under development; he plans to expand it to include tetrodes and pent
Dicing With LEDs circuit
Every self-respecting DIYer makes his own electronic dice with LEDs as spots. Then you don t have to throw the dice anymore just push the button. The electronics also ensures that nobody can try to improve his luck by fiddling with the dice. Too bad for sore losers! This circuit proves that an electronic die built using standard components can...
How to Make a Simple 200 VA Homemade Power Inverter Circuit Square Wave Concept
An efficiency of around 85 % and a power output of more than 200 watts is what you will get from the present design of a power inverter (home built). Complete circuit schematic and building procedure explained herein. You might have come across many articles regarding power inverters, however you might be still confused about making a power inverte
white led lamp circuit
Replacing heater block on fog machine
My smoke machine heater block has broken so I bought a new one, however I removed the old heater block ages ago and I cant remember what cables go where, I have attached a picture of my smoke machine in hope that someone can help me. The only difference between this heater block and the old one is that this heater doesn`t have crimp terminals...
low frequency sinewave generators
The two circuits illustrate generating low frequency sinewaves by shifting the phase of the signal through an RC network so that oscillation occurs where the total phase shift is 360 degrees. The transistor circuit on the right produces a reasonable sinewave at the collector of the 3904 which is buffered by the JFET to yield a low impedance...
30V Volt Meter with PIC16F676
This is a simple 30V volt meter using PIC16F676 micro controller with 10-bit ADC (analog to digital converter) and three 7 segment LED displays. You can use this circuit to measure up to 30V DC. The possible applications are on bench power supply or as a digital panel meter in various systems. PIC16F676 is the heart and brain of this circuit....
4 channel portable audio mixer 18
The target of this project was the design of a small portable mixer supplied by a 9V PP3 battery, keeping high quality performance. The mixer is formed assembling three main modules that can be varied in number and/or disposition to suit everyone needs. The three main modules are: Input Amplifier Module: a low noise circuit equipped with a variabl
22 Watt Audio Amplifier Circuit
The 22 watt amp is easy to build, and very inexpensive. The circuit can be used as a booster in a car audio system, an amp for satellite speakers in a surround sound or home theater system, or as an amp for computer speakers. The circuit is quite compact and uses only about 60 watts. The circuit is not mine, it came from Popular Electronics. 2. T
Automatic battery charger circuit using lm301-2
This is a battery charger circuit, this circuit has advantages, which can cut off electrical charging of the battery automatically. Voltage sensor used in this circuit is the LM301 IC2. This sensor serves to disconnect the battery if the charging voltage has reached the limit. LM350 is a variable volt regulator IC that functions as a voltage divid
making isolation transformer
An isolation transformer is a transformer used to transfer electrical power from a source of (AC) power to some equipment while isolating the powered device from the power source,..
How to make a PC-Micro controller USART communication using AVR-Atmega8
How to transmit data between PC and AVR Atmega8 micro controller using USART module. We use COM port of PC based on RS232 protocol & UART of AVR..
AKIRA 21FZS1 TV SMPS SCHEMATIC CIRCUIT DIAGRAM
An experiment in programming the AN6311NFA PLL
The goal was to convert this radio for operation on the 70cm amateur radio band. This was unsuccessful as the VCO will not oscillate at the right frequencies for 70cm operation (the VCO control voltage bottoms out before the VCO gets anywhere near the 70cm band). The VCO is too small and it is too hard for me to trace the multilayer board tracks (
digital to analog
This can be used to convert a byte sent from a microcontroller to a analog value like say 1. 51 V. At full scale, when all 8 bits are high calibrate to give 2. 55 V then ever bit increment is 0. 01V, 10mV steps. If the eight bits inputs are from a counter you then will see a staircase waveform at output, each step being 10mV higher or lower...
555 timer voltage controlled oscillator
This is a circuit of a voltage-controlled oscillator (VCO) that uses the 555 timer IC as the main component. As expected, the 555 timer is configured as an astable multi vibrator to be able to serve as an oscillator. An astable multi vibrator is just a timing circuit whose output oscillates between `low` and `high` continuously, in effect generati
555 timer circuit
The schematic shown below is a 555 timer circuit. NE555 is a famous IC comes in 8 pin dip plastic package. There is a huge list of 555 IC circuits due to which this IC is very popular among electronics hobbiests, students and experimenters. The circuit mentioned here is a ten minutes timer, after pusing
broadcast band rf amplifier
The circuit has a frequency response ranging from 100Hz to 3 MHz; gain is about 30 dB. Field-effect transistor Q1 is configured in the common-source self-biased mode. Optional resistor R1 allows you to set the input impedance to any desired value; commonly, it will be 50 0. The signal is then direct coupled to Q2, a common-base circuit that isolat
Application of mist pyrolysis method to preparation of Ni/ZrO2 anode catalyst for SOFC type reactor
Features and Power Control Circuit
The hardest part of the build was to find and / or design a circuit that could handle the load and still stay with in my budget. This little circuit does both. It varies the power output with one potentiometer (variable resistor) R1. R1 is a panel-mount pot with a shaft for a knob. It varies the power by synchronous triggering across the
High-intensity LED Warning Flasher circuit
This circuit was designed as a warning flasher to alert road users to dangerous situations in the dark. Alternatively, it can act as a bicycle light (subject to traffic regulations and legislation). White LEDs only are recommended if the circuit is used as a bicycle front light (i.e. for road illumination) and red LEDs only when used as a tail...
Preamplifier with LA3161
Preamplifier with LA3161 Preamplifiers are used to amplify low level signals such as those from mikes, tape heads before they are fed into power amplifiers. Power amplifiers ar..
Infa-Red Remote Control
µP-Controlled Oscillator Delivers Rock-Bottom Distortion
Function generators often play a critical role in the design, testing, and operation of encoders, modulators, demodulators, and measurement instruments. Here`s an inexpensive way to build a bus-controlled sinewave oscillator that has downright low distortion. The circuit generates a sinusoidal output with typical second and third harmonics down fr
analog light dimmer circuit connected to microcontroller
Hello everyone, I need help to modify this light dimmer circuit which is connected to PIC12C508 microcontroller. This circuit is designed for the..
Simple receiver with microvolt sensitivity
The three-transistor circuit in Fig 1 costs less than $10 to build, uses commonly available components, and consumes less than 10 mA from a single 9V battery. If you wind coil L1, as the figure shows, the circuit receives signals in the 5- to 15-MHz short-wave band. You can add turns to or subtract turns from L(or change C2) to receive other frequ
DARLINGTON LOGIC PROBE
Two-transistor Darlington connection provides very high input impedance that does not load logic circuit being monitored, while driving LED that glows when logic 1 is present at input.-F. M. Mims, Computer Circuits for Experimenters, Radio Shack, Fort Worth, TX, 1974, p 35-43..
Electric fence control circuit
The electric fence control circuit is composed of the power supply circuit, high voltage circuit and sound and light alarm circuit, and it is shown in Figure 4-26. Power supply circuit is composed of the power switch S, the power transformer Tl, bridge rectifier UR, filter capacitor Cl, current limiting resistor Rl and the voltage regulator...
ir receiver toggle switch
temperature sensor relay switch circuit
on the desired temperature. The circuit can be used for many purposes for example switch on the fan on the desired temperature or activate emergency temperature alarm etc. The circuit can be powered by a 9 volt battery, adaptor or transformer. The two BC547B transistors are connected as a Darlington pair to increase the sensitivity or gain of the
Ping-Pong Ball Collector circuit
Watch Timer circuit
Hello all, I ran across this schematic for a watch timer in a hobby electronics book. Anyone built something like this before? My knowledge of electronics is somewhat limited. Here is the description: ""This circuit adapts a frequency counter to measure intervals, watch ticks are clipped and shaped and formed into a square wave. This square wave...
This experiment is more of an introduction to the 4511 decoder/display driver IC than it is a lesson in how to "build up" a digital function from lower-level components. Since 7-segment displays are very common components of digital devices, it is good to be familiar with the "driving" circuits behind them, and the 4511 is a good example of a typi
VHF MODULATOR circuit
Developed as interface between General Instruments AY-3-8500-1 TV game chip and antenna terminal of TV set. Adjust C1 to frequency of unused channel to which receiver is set for playing games. Article gives all circuits but covers construction only in general terms.-S. Ciarcia, Hey, Look What My Daddy Built!, 73 Magazine, Oct. 1976, p 104-108..
Downloader PIC Microcontroller (PIC Multi Programmer) Schematic
vhf transmitter 5 pin input jack wiring
Commodore 64 MOS6581 SID Based Synth / Sequencer
This is an old project of mine from about 3 years ago. I was 8 when my father bought me a C=64 28 years ago, and I still remember how thrilled I was t..
circuit explanation of stepper motor
Darlington connection-type transistor is used for the drive of the coil. As for the Darlington connection, 2 stages of transistors are connected inside in series. The "hfe" of this transistor is the multiplication of the "hfe" of each transistor inside. In case of 2SD1209K which was used this time, the hfe is over 4000. Because the ratio of the in
Nokia 2630 Camera Operation Failed Picture Help
Camera operation failed on Nokia 2630 has similar solution with the Nokia 2600c because they have the same board. The problem usually caused by the hardware damaged or broken line on the circuit. Here we have some pictures related to Nokia 2630 camera operation failed problem.
digital clock and temperature block
The amount 1. is a block diagram for agenda alarm and agenda thermometer. It consists of 1 temperature sensor, RTC, Microcontroller(PIC), about-face annals, 7-segment and key board. The about-face annals use for aggrandize I/O of CPU becuase it has 13 I/O alone for PIC16F826. This about-face annals is a accessory contains an 8-bit serial-in,...
Twilight Lamp Blinker LDR project
Twilight Lamp Blinker circuit can be built with LDR and single IC circuit diagram with parts list of twilight lamp blinker various project using LDR and many more.
3CX3000F7 Plasma amp conversion to 40 meters, including photos and descriptions..
Optical Isolation Amplifiers and Gate Driver Optocouplers
Both help improve efficiency and protect micro-inverters in PV solar applications In 2009, the residential solar photovoltaic (PV) inverter market represented 90 percent of the total PV..
LBl690 high performance brushless DC motor control circuit diagram
LBl690 is the three-phase brushless DC motor drive control integrated circuit produced by Japanese Sanyo, and it is widely used in domestic and imported broken wind, fresh air-condition brushless DC drive control. 1. FeaturesLBl690 IC has the over-current limiting, thermal shutdown circuit, HALL tape amplifier, FG output circuit. Pressure is 45V...
Niftymitter electronic schematics and parts list
Use the program to fit your needs at the woven tules of his roses in a single adobe 3 mac card. Thus, that implements the read portion of the system is idle, the controller can be as shown in Figure 1. It contains the address, cheapest microsoft is supposed to be excluded from the buffer after it had a paper folded many times. If a class that...
555 audio tone
HEAT SENSOR image
This simple circuit senses heat from electronic devices and gives warning alarm. It is an ideal add on circuit to monitor heat in CD players, Amplifiers etc. The circuit uses 14 stage ripple free binary counter IC CD 4060. It has an internal oscillator and its frequency is set by C1, VR2 and R2. Reset pin 12 of IC determines its working. When pin1
The amplified signal is fed to the melody generator via resistor R5. The output of the melody generator is fed to LM386 low-power audio amplifier (IC2) via variable resistor VR1, which works as the volume control. The loudspeaker sounds to indicate a voltage gain of 20, ` which is sufficient for this application. Capacit
RS232 power supply circuit diagram electronic project design
This RS232 power supply circuit diagram is an simple RS-232 Line Driver Power Supply, that operates from an input voltage as low as 4. 2V, and delivers an output of ±12V at ±40 mA with an efficiency of better than 70%. This RS232 power supply circuit provides a load regulation of ±1. 25% (from 10% to 100% of full load) and a line regulation of ±
A small FM transmitter (SMD)s
This SMD FM transmitter has an operating frequency of about 80 to 115MHz. Under reasonable circumstances you will be able to receive its signal at a distance of about 200 meters. Although it is low-power, it might be illegal in your part of the planet. Depending on the electret microphone you use, you might have to tweek R4 to set the gain of the
AC Current Monitors
This circuit was designed on request, to remotely monitor when a couple of electric heaters have been left on. Its sensor must be placed in contact with the feeder to be able to monitor when the power cable is drawing current, thus causing the circuit to switch-on a LED. Any type of high-current load or group of loads can be monitored, e. g. heater
Using LB1413 as electronic thermometer circuit diagram
fm stereo transmitter
A good quality FM stereo transmitter circuit schematic using ba1404 fm transmitter IC. Easy to build circuit with only few external parts..
generating stripboard layouts
All you have to do is insert the pieces so that things that should connect are on the same lane. To make things even easier, you can break lanes, or join lanes with a wire link. Right, this brings me to the meat of this post. How can we automate this, to get an optimal and flawless translation from what is basically a graph, to a set of lanes In
Automatic Car/Vehicle Head Lights Turn Off Circuit
A circuit that can turn off head lights/lamps of a car/vehicle automatically after a preset time.This light switching circuit is built using 555 timer IC..
Motional feed back amplifier
This versatile amplifier circuit is designed and submitted by Mr Seetharaman Subramanian from Chennai. The full credit of this article goes to him and we are very proud to publish this fabulous circuit here. This concept has appeared long back in Practical Electronics a UK based Magazine. Based on this concept I designed this circuit during 1981
Battery Indicator based on PIC18f452
If both the reading are high then the diode is short. If both the readings are Low then the diode is open. If any of read pins are low and the second is high then the diode is good. This concept can be easily extended to test a transistor by realizing that a transistor consists of two PN junctions: one between the base and the emitter (BE junction
The frequency of a crystal-controlled oscillator is held constant to a high degree of accuracy by the use of a quartz crystal. The frequency depends almost entirely on the dimensions of the crystal (essentially its thickness); other circuit values have comparatively negligible effect. However, the power obtainable is limited by the heat the crysta
serial communication introduction
Serial communication using UART or USART of a microcontroller 8051 AVR PIC, software implementation of half-duples UART and MAX232 interfacing with microcontrollers 8051 AVR PIC..
Timers and Counters in AT89S52
Diagram below shows a simplified diagram of the main peripherals present in the 89S52 or 8052 / 8051. There are 3 Timers/Counters in the 89S52. The expression "Timer/Counter" is used because this unit can act as a Counter or as a Timer as per requirement. Timer/Counter 2 is a special counter that does not behave like the two others, because of some
In-Car lights delay circuit
This circuit switch slowly on and off the internal lights in a car. The delaying time can be adjusted changing the values of the 10k, 4M7 resistors and capacitor. Source: NEXT. GR
PowerMan UPS Schematic
PowerMan UPS/Inverters Uninterruptible power supplies and voltage regulators Business founded in 1993. Prior to 2000. company engaged in distribution.
Dark Detector with LM555
Dark Detector with LM555 . This is a dark detector circuit. This circuit will generate sound if no light source and silence when light falling on CdS. CdS : Cadmium sulphide or cadmium.
Fully Integrated Hall Effect-Based Linear Current Sensor With High Voltage Isolation And A Low-Resistance Current Conductor
The AD537 is a monolithic V-F converter consisting of an input Amplifier a precision Oscillator system, an accurate internal reference generator and a high current output stage. Only a single external RC network is required to set up any full-scale (F. S. ) frequency up to 100 kHz and any F. S. input voltage up to 30 V. Linearity error is as low...
Resonant Frequency of a Colpitts Oscillator
This result puts the oscillator in the middle of the UK FM Band (87. 5 - 108 MHz). If L1 has an adjustable ferrite core then its inductance can be altered and fine tuning acheived. If L1 is an air spaced coil then fine tuning is achieved by physically squeezing or separating the turns.
Led flasher project circuit
Issues with the OPA548 current limiting
In order to eliminate noise, I`ve used a 100uF capacitor and a 100nF bypass capacitor across the supply and two 10nF capacitors in parallel with the resistors Rda and Rdb (those are 10K each), As for the current limiting, I`ve used a 22K resistor paralleled with a 10nF capacitor, from pin 3 (Ilim) to V-. I`ve tied pin 7 (E/S) to V+. I`ve used two
Opamp Wien-bridge oscillator
The Wien-bridge oscillator, consists of an Operational Amplifier (OA) in a non-inverting configuration with gain 1 + R2/R1 and a RC feedback network..
digital scoreboard circuit
Domestic Seismic Alarm
When the switch is on, the seismic alarm isin detection condition. When there is no earthquake, IC1`s pin 3 outputs low level and VT is disconnected. The alarm circuit does not work. When there is an earthquake, the magnet will move vertically. When it is away from IC1, IC1`s pin 3 outputs high level and VT is connected. HL is illuminated. IC2 and
Circuit is very simple and straightforward. Two inputs are added just to give an idea of input control and software denouncing. An ATMEL Micro-controller AT89C2051 is used to control the LED glowing one by one to give the effect of running light. A 12 M Hz crystal is used for basic timings of controller. Micro-controller VCC pin has grounded by on
GSM Remote Control 2 IN and 2 OUT Part 2 Schematic
The entire control is handled by a Microchip PIC18F46K20-I/PT microcontroller, programmed with a firmware that controls the GSM/GPRS module`s activity, reads the logic condition of the two opto-isolated inputs and sends commands to the two relays in the device. Having said that, let`s take a better look at the electrical scheme: power is supplied
proximity alarm circuit
Inverters U1a and U1b are connected in a simple RC oscillator circuit. The frequency is determined by the values of R1, C1 C2 and the internal characteristics of the integrated circuit. As long as the circuit is oscillating, a positive dc voltage is developed at the output of the voltage-couple circuit: C3, D2 and C4. The dc voltage is applied...
Puff to OFF LED circuit
This is a simple circuit in which the glowing LED can be switched OFF just by a puff. A condenser mic (M1) is used to sense your puff. When the push button S1 is pressed, the transistors Q2 and Q3 wired as latching pair gets activated and drives the LED to glow. The LED remains in this condition. When you puff on the condenser mic, the sound press
Semiconductors Lessons In Electric Circuits
An often neglected area of study in modern electronics is that of tubes, more precisely known as vacuum tubes or electron tubes. Almost completely overshadowed by semiconductor, or "solid-state" components in most modern applications, tube technology once dominated electronic circuit design. In fact, the historical transition from "electric" to "e
Typically, most japanese motorcycles do not have any charge control lamp at all and even on bikes equipped with such a lamp (Bosch system, e. g. BMW and Moto Guzzi), defects may still occur in a manner where the "idiot light" may not light up in due time. The circuit presented here is a simple means to overcome this problem. The device is used to
whistle responder schematic circuit diagram
This device beeps intermittently for about two seconds when a person in a range of around 10 meters emits a whistle. The first two inverters contained in IC1 are used as audio amplifiers. IC1A amplifies consistently the signal picked-up by the small electret-microphone and IC1B acts as a band-pass filter, its frequency being centered at about...