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 32
Automatic Switch Project 2
The eyes of the switch control system allow the microcontroller`s "brain" to know where the trains are located on the layout. This insures that only one train is on the main line at a time and that the switches are set so that the train returns to the proper siding. There are many ways to sense whether or not a train is at a particular spot on a
Cut Phone Line Detectors
Optical tachometer schematic diagram
It requires a 15VDC adapter. An electrolyte capacitor is needed across the regulator input. If the capacitor is added in 7812`s OUT pin w. r. t. ground, then a bypass diode should be added in reverse to IN and OUT of the regulator, just to save it from reverse voltage.
Car Battery Charger Circuit
The car battery charging current is automatically limited to 4. 2A. If there is a 600mV voltage on R1 (4A thru it), then the T1 transistor starts to conduct. Excessive charging current is avoided because the current value on T3 ²s base is limited. The difference between applied load current (at T4 ²s collector) and real voltage of the battery is
Long range FM transmitter
This is very stable, harmonic free, long range fm transmitter circuit which can be used for fm frequencies between 88 and 108 MHz. This can cover 5km range (long distance). It has a very stable oscillator because you use LM7809 stabilizer which is a 9V stabilized power supply for T1 transistor and for frequency adjustment that can be achieved by u
Digital Radar Speedometers
This circuit is a Digital Radar Speedometer. It allows us to evaluate the speed of any object moving, especially cars and other vehicles. The speed is calculated in kilometers per hour (KPH). Its display has three digits. This radar works with the laser reflexion. It sends laser radiation to the object and this object reflects the laser radiation
The Selmer Lyricon Synth Flute circuit
8 Relay Control Circuit Schematic Diagram
FM stereo demodulator circuit based on AN7415. 3V operation good channel seperation
AN7415 based FM stereo demodulator circuit. 1.6 to 7V operating voltage range. High gain and low distortion..
Inductance Meter Adapter Circuit Turns Your Digital Voltmeter to Inductance Meter
Measuring inductance is important in making your hand-made inductors, especially when you do-it-yourself (DIY) your coil winding. An inductance meter adapter..
switches Default-on latch-off MOSFET power switch
It should default on when first connected, but if a particular signal goes high for a small amount of time (say, 10 microseconds, ) then it should turn off, and stay off. It`s the "default on" that gives me trouble. The closest I can get is something like this: From null, "OFF" is floating. Supply 15V, and the capacitor starts out acting like a...
overcurrent detection circuit
This motor overload circuit does not simply disallow overloading since it is permissible to overdrive a system but only if it is done for a short time (typically dependent on heat buildup). An overload detection circuit protects a motor against currents above rated current that persist for certain exposure times. The allowable exposure times are i
Low pass filter circuit 10KHz using uA741
This be the circuit filters 10KHz low size frequencies s use IC op-amp the highly popular number uA741. By this circuit convenients for to apply to input and output of the circuit changes analog signal be digital or the circuit changes digital signal be digital. In sound system of digital for synthetic the voice or music give for make wave form ou
fm stereo transmitter ba1404 diagram
power supply design 5v 7805 voltage regulator
For making a power supply designing‚ of each and every component is essential. ‚Here I`m going to discuss the designing of ‚regulated 5V Power Supply. NOTE : Any transformer which supplies secondary peak voltage‚ up to35V can be used but as the voltage increases size of the transformer and power dissipation across regulator increases.
Loudspeaking crystal radio receivers
A lots of radio amateurs have an interest to power a simplest radio receivers with the "free energy", i. e. the energy, taken by the receiver antenna directly from the air. The circuits described here can provide a radio reception using a loudspeaker. The question of how much power can get out of a signal from an antenna, and how to build a loudspe
Telephone Ringer Circuit
The Telephone project posted here is the a telephone ringer which producespleasanttunes when a call is placed to your number. The tunes produced by telephone ringer here are more melodious andsoothing compare to those of old telephone instrument and piezo buzzer in the current electronic telephone instruments. The circuit is based on the musica
Digital frequency counter
The frequency counter has to count the number of cycles per second of an incoming signal. Hence we need a device to count. In electronics circuits, counter ICs are available for counting. These IC`s can count the input pulses. The count is given as coded output from the IC (in binary form or BCD form). The count must be converted into decimal digi
AF2310 radio controlled motor circuit design project
This circuit is very similar with a car radio controlled toy with seven control functions: forward, forward-left, forward-right, backward, backward-left, backward-right, and stop. Also you can use this radio frequency circuit for some other electronic circuits that require a simple wire less motor controller. The remote control work`s at a frequen
12V to 220V converter circuit Schematic Diagram
This DIY 12V to 220V voltage converter is build with CMOS 4047 that is the main component of this small voltage converter that transforms a 12V DC into 220V AC. 4047 is used as a astable mutivibrator, at pins 10 and 11 will have a symmetrical rectangular signal wich is amplified b 2 Darlington transistors and finally reach the secondary coil of ma
USB Power Injector For External Hard Drives
A portable USB hard drive is a great way to back up data but what if your USB ports are unable to supply enough juice to power the drive A modified version of the Silicon Chip Usb Power Injector is the answer. For some time now, the author has used a portable USB hard drive to back up data at work. As with most such drives, it is powered direc
APPLIANCE CONTROL USING TIMER - PROJECT
I am going to present you fabulous Electronic project, DEVICE CONTROL USING TIMER. By using this circuit you can turn ON an appliance at a desired time for a specific time interval. You can use this concept to control the operation of a furnace or central air conditioning unit so that it comes on at a desired time. For example, a timer may be
IR remote control computer interfacing
This article tries to get you some idea how to interface IR remote controllers to computer. Possible applications could be controlling your computer your TV`s remote control or controlling your VCR using computer. This circuit was posted to sci. electronics newsgroup long ago. This circuit has been very useful to me because I based my first IR remo
Logic Probe with Seven Segment Display
Logic probe is circuit that indicates the logic state of the node of any TTL logic circuit. It will work if we must supply the probe with the same power of..
bias current compensation circuit
This is design circuit of bias current compensation circuit. This circuit can operate from MW source resistances with little increase in the equivalent offset voltage. This circuit is based on LM11. This is the figure of the circuit. This is impressive considering the low initial offset voltage. The situation is much improved if the design can be
economy radar detector
This circuit uses a 1458 dual op-amp to form a radar detector. C1 is the detector of the radar signal. The first op-amp forms a current-to-voltage converter and the second op-amp buffers the output to drive the piezo transducer. R5 sets the switching threshold of the second op-amp; normally it is adjusted so that the circuit barely triggers on bac
ir infrared detector circuit diagram
Men in particular enjoy the convenience of television remote controls often to the annoyance of their female partners. Men apparently want to know what they re missing when the TV is tuned to a particular program, so they like to keep zapping to other channels. With the remote control in their hands, they feel like they are the lord and master...
fm tracking transmitter circuit
This is a design for the tracking transmitter of audio tone in FM band frequency. The circuit can be used a signal transmitter or remote control transmitter. The circuit is use only the available components. The range of the transmitter is 100 m in the distance using 9V power supply and with a matching antenna. The circuit is built by 555 timer IC
High DC Voltage Current Sensing
LTC6101 op-amp can be used to build High voltage current monitoring/sensing. This circuit can senses current in 500 volts system. Here is the schematic diagram..
S1L9251X Cd-rom 48x Rf Amp Semiconductor
O The SA1021 integrated Radio receiver circuit is for portable Radios stereo as well as mono, where a minimum of periphery is important in terms of small dimensions and low cost. It is fully compatible for applications using the low-voltage micro tuning system (MTS). The IC has a frequency locked loop (FLL) system with an intermediate frequency of
wein bridge oscillator
Simple variable frequency oscillator
Simple variable frequency oscillator. This is a very simple circuit utilising a 555 timer IC to generate square wave of frequency that can be adjusted by a potentiometer. With values given.
Touch Volume Control Circuit
Touch controls are not only used to switch devices on or off. They can also be used to control different functions. One good example is the TV remote control. If it is very important to keep the activated functions for a long period of time, it is always better to use a digital memory system. However, if small drifts in the control status is accep
2400 MHz RF amplifier circuit diagram using PM2107
applications in the 2400 MHz ISM band. This two stage RFIC amplifier is off-chip matched to provide optimum performance for a variety of applications. Operating from a 5 volt supply, the PM2107 can produce 1 watt of saturated output power with 45% typical efficiency. The inductance to the microstrip ground plane should be as low as possible in gro
AK4532 Internet/Network/General Purpose Multimedia Audio CODEC
AMIS-49200-XTP is a sub package of AMIS-492X0, If you need see the description, please click AMIS-492X0. If you need AMIS-49200-XTP`s datasheet, please download it from below. By ON Semiconductor
Numeric water level indicator- liquid level sensor circuit diagram with 7 segment display
Here we define 7 levels in thereservoir. The sensed values are connected to an encoder circuit. The encoder circuit consist of a 74148 IC, which is a 8 line to 3 line encoder. Next section is the HEX Display` which is a special type of 7 segment display. It is easier to use than the regular seven-segment display because it is already decoded. Each
audio frequency meter
This is a circui for audio frequency meter. This circuit uses 555 IC as a mono stable multi vibrator (one-shoot trigger). A mono stable multi vibrator can act as a frequency-to-voltage converter because it produces a fixed pulse width, with the repetition rate/density is proportional to the triggering input frequency. This is the figure of the cir
The NOT gate
The single-transistor inverter circuit illustrated earlier is actually too crude to be of practical use as a gate. Real inverter circuits contain more than one transistor to maximize voltage gain (so as to ensure that the final output transistor is either in full cutoff or full saturation), and other components designed to reduce the chance of acc
Automatic Gain Control Microphone PreAmp
This microphone preamplifier incorporates automatic gain control, which keeps the output level fairly constant over a wide range of input..
Triode Frequency Conversion at FM-VHF
four bit shift register using dff
shadow sensor circuit ldr circuit
Open Source Automation Wiki
A multivibrator is a form of relaxation oscillator which comprises two stages that are coupled so that the input of one is derived from the output of the other. A multivibrator is basically two amplifier circuits arranged with regenerative feedback. One of the amplifiers is conducting while the other is cut off. The Astablemultivibrator circuit...
laser diode driver circuit
This is circuit design for a laser diode driver can be implemented using voltage-controlled current source. This simple linear laser diode driver gives cleaner drive current than a switched (PWM) drivers. This circuit is based on OPA350 IC. This is the figure of the circuit. A Howland current pump with a current booster is used as the basic of thi
Ultrasonic parking sonar circuit design project
A very simple ultrasonic parking sonar electronic project can be designed using this schematic circuit. This ultrasonic parking sonar electronic project has an adjustable detection range from 5 cm up to 1. 5 meters and a detection angle of 5 degrees. This ultrasonic parking circuit has a transmitter frequency of 45kHz and require a dc power suppl
Nice bunch of fresh AT89 projects
10x TDA1543 NOS DAC
In supply section after bridge rectifier and smoothing capacitor is used common voltage regulator LM317, which has with R1 and R2 adjusted output voltage about 8V. Supply line goes through inductor to DAC chip for theoretically lower HF interference which goes on the power lines. DACs have current outputs which are converted to the voltage...
Acceleration Monitor using ADXL202 and AVR
The schematic show that the AccelR8 only uses 3 IC`s. An AVR 8515 microcontroller do the calculation work and controls the other circuits. An MAX603 controls voltage and power-on/power-off. And the chip that makes it all possible, the ADXL202 from Analog Devices measures the acceleration. This chip is a small wonder. It uses a tiny micro machined
Video Switch for Intercom System
Nowadays a lot of intercom units are equipped with video cameras so that you can see as well as hear who is at the door. Unfortunately, the camera lens is perfectly placed to serve as a sort of support point for people during the conversation, with the result that there`s hardly anything left see in the video imagery. One way to solve this problem
IR Remote Control Receiver
With many audio systems consisting of separate units, you`ll oftennd that due to economic reasons only the amplifier has a remote control receiver module. The control signals are then sent to the other units using patch cables. The tuner and CD player, for example, won`t have a built-in receiver module. When the tuner from such a system is bou
VOX (Voice-Operated Switch)
This schematic diagram below show a circuit of VOX Box (voice-operated switch). This circuit consist of a Schmitt trigger, a relay driver, and microphone..
1 Circuit and Wiring Diagram * 2 Parallel Phone TapCircuit * 3 Mobile/Cell
Selfrunning Free Energy 5 KW Kapanadze 5
The 22 turn coil is on top of the 84 turn coil. It makes a difference having this coil connected. I have tried with a 1kw heater and worked better but if I leave it on for too long I am sure it will blow it too. The wire in the heater normaly is not as bright as when connected in the circuit here. I will get some 500w bulbs too. I was talking...
1K2 Packet Radio modem with BA758
Audio Level Meter circuits
Simple Direct Conversion Receiver
pierce xtal oscillator circuit
This circuit is conventional Pierce type oscillator that uses a JFET. The circuit uses fundamental mode crystals. It has decent performance and reliability if we use a low noise JFET. This is the figure of the circuit. The feedback is controlled by the C1 Capacitance from drain to ground. Adjusting the frequency can be done by adjusting a shunt
Modular Music Box Arduino polyphonic audio
Before I emailed Pablo Gian Villamil and he sent me on a link to his class notes (yay!) for Generating polyphonic sound with Arduino I tried to work out his circuitry from his various blog posts and component listings CMOS Hex Schmitt Trigger Inverter Integrated Circuit (74C14) or CMOS Quad NAND Gate Schmitt Trigger Integrated Circuit (CD4093)
* 2 x 47k ohm resisters anything from 22k to 100k ohm should work. Value of these changes the timing of blinking (larger the value, slower the blinking).
555 four words cycle neon light light control circuit
This control circuit is composed of the AC step-down rectifier circuit, the astable multivibrator, the timing control circuit, the optocoupler circuit and the SCR driving circuit.etc. As the figure 17-61 shows. The astable multivibrator is composed of the IC2(555) and R2?R3?RP1?C3.etc. It`s frequency depends on RC`s charging and discharging time...
Effect of various pulse wave forms for pulse-type magnetic flux pump
Car Battery Failure Detector
A car battery deteriorates in use and its life seldom exceeds four years. When new, its voltage may drop to only 2V while cranking the engine. As the batt..
QRP HF LINEAR AMPLIFIER Circuit
This project was a particular surprise for me in that the BC547 (equiv 2N2222) can be used to build a 500mW linear amplifier covering the entire HF band with excellent spectral purity and no neutralizing at all. Ugly-bug construction was used but I dare say that the good results are partly to do with the method of construction. The circuit is fair
This paper describes the process by which a control circuit for a stepper-motor was designed
This paper describes the process by which a control circuit for a stepper-motor was designed. Due to the nature of the stepper motor, the control circuit had to be a state machine that cycled through four output states based on two input conditions (direction and enable)
The interface circuit between single-chip accelerometer MMA1220D and microcontroller
The microcontroller within A / D converter can use PIC MCU within A / D converter produced by the Microchip. MMA1220D`s state end and self-test end are connected to the P1, P0 ports of ?C, its output voltage is sent to the A / D converter input end. C1, C2 are the power supply decoupling capacitors. A / D converter`s reference voltage side (...
audio power amplifier circuit
Negative Charge Pump with Ring Oscillator
In principle, the square wave oscillator doesn`t have to be a 555 timer, it could be a ring oscillator using inverters as you propose. In practice, using 4000 series CMOS logic for example, the negative output voltage produced would not be able to provide a great deal of current due to the current sourcing limitations of the IC. If the amount of...
PC SMPS PWM chip CG8010DX16
Here are the datasheet and the circuit dram of a PC Switching Power Supply using the IC CG8010DX16..
Extending the sound beeper volume of an Multimeter
Frequency counter 400Hz to 50MHz with PIC 16F84
It consists only from Microchip PIC 16F84 cpu and LCD text module. Author states that this counter is capable metering frequencies from 400Hz to 50MHz. I used faster, 20MHz version of 16F84A-20I/P, and it managed to count 80MHz oscillator output.
microcontroller wake up lcd
avr microcontroller circuit
Arduino Uno has a ATMEGA328P-PU microcontroller, and bunch of other stuff on the board. I`d like to program the chip without the Arduino software, and only the minimum of other components. I want to eventually create things without the cost of Arduino, and I want to learn about the other parts on the board and add them back as as needed. I`m...
The Geiger tube needs a high voltage sup-ply which consists of Q1 and its associated components. The transformer is connected in reverse; the secondary is connected as a Hartley oscillator, and RI provides base bias. Dl, D2, C4, and C5 comprise avoltage doubler. RV1 should be set so that each click heard is nice and clean because over a certain...
High voltage ohmmeters
Most ohmmeters of the design shown in the previous section utilize a battery of relatively low voltage, usually nine volts or less. This is perfectly adequate for measuring resistances under several mega-ohms (M ©), but when extremely high resistances need to be measured, a 9 volt battery is insufficient for generating enough current to actuate...
High-Speed Photos of Low-Speed Impacts
The goal is to freeze different stages of some fairly quick process (at least when compared to the time resulotion of the human eye). Since I don`t have fancy toys like a high speed film camera, lack of good equipment has to be compensated with a smart setup applying just a an ordinary consumer-type digital camera and some self-made electronics. U
Fluorescent lamp electronic ballast
The fluorescent lamp electronic ballast circuit is composed of the rectifier filter circuit, high-frequency oscillator circuit and output circuit, and it is shown in Figure 3-202. Rectifier filter circuitis composed of the rectifier diodes VDl-VD4 and filter capacitors Cl, C2. High-frequency oscillator consists of the transistors VI, V2,...