Top Circuits Page 216
- Page 216
-
-
-
This circuit enables observation of movement between other stroboscopes. Generation of rectangular signal is based on NE555. This circuit requires a low power supply that is made from a simple transformer TR1, traditional rectifier bridge and zener diode.....
-
12 LEDs can be arranged in a circle to represent the 12 hours of a clock face and an additional 12 LEDs can be arranged in an outer circle to indicate 5 minute intervals within the hour. 4 additional LEDs are used to indicate 1 to 4 minutes of time..
-
A pulsating light for a certain signaling. Voltage was 230V. So I decided to make a simple circuit, consisted of a LED diode, two capacitors, two resistors, a diac and a diode. Activity of the circuit is extraordinarily simple. The capacitor charges by the....
-
This 40W fluorescent lamp inverter allows you to run 40W fluorescent tubes from any 12V source capable of delivering 3A. This is basically a larger version of the 12VDC Fluorescent Lamp Driver and can be used to light regular or blacklight tubes. # Wind....
-
-
-
This system, composed of two opto-insulated circuits, allows the data transmission per infra-red network device between two computers. For example, someone can transfer his files starting from his desktop computer to his laptop computer without using any....
-
The 7815 regulatates the positive supply, and the 7915 regulates the negative supply. The transformer should have a primary rating of 240/220 volts for europe, or 120 volts for North America. The centre tapped secondary coil should be rated about 18 volts at....
-
This simple charger uses a single transistor as a constant current source. The voltage across the pair of 1N4148 diodes biases the base of the BD140 medium power transistor. The base - emitter voltage of the transistor and the forward voltage drop across the....
-
This circuit above uses a 13 volt zener diode, D2 which provides the voltage regulation. Aprroximately 0. 7 Volts are dropped across the transistors b-e junction, leaving a higher current 12. 3 Volt output supply. This circuit can supply loads of up to 500....
-
-
-
-
-
The circuit is built around two 555 timer ICs. U1 and U2. U1 is wired as a variable duty cycle oscillator with a constant time period of around 0. 1 second. Duty cycle can be varied from 0 to 100 per cent by R4 potentiometer. The output of U1 (pin 3) is....
-
This circuit controls resistive and inductive loads up to 2, 500W. Its main functional device is an integrated phase control circuit - Siemens TLE3103. It contains its own power supply, a zero voltage crossing detector circuit and a logic driver. An....
-
-
The LM317T is a adjustable 3 terminal positive voltage regulator capable of supplying in excess of 1. 5 amps over an output range of 1. 25 to 37 volts. The device also has built in current limiting and thermal shutdown which makes it essentially blow-out....
-
The LM317T output current can be increased by using an additional power transistor to share a portion of the total current. The amount of current sharing is established with a resistor placed in series with the 317 input and a resistor placed in series with....
-
This is the schematic for an FM transmitter with 3 to 3. 5 W output power that can be used between 90 and 110 MHz. Although the stability isn`t so bad, a PLL can be used on this circuit. This is a circuit that I`ve build a few years ago for a friend, who....
-
L1, L2 Wires of coper (smaltwme`na) with diameter 0, 4mm wrapped in plastic support of diameter 6-7mm of perjstrofjkoy` core. For the L1 you wrap 13 coils. For the L2 you wrap 4 coils. (As in the receptor CB. ) ANT1 Aerial for CB (For the trials is enough a....
-
-
This circuit runs a fast battery test without the need of power supply or expensive moving-coil voltmeters. It has two ranges: when SW1 is set as shown in the circuit diagram, the device can test 3V to 15V batteries. When SW1 is switched to the other....
-
This circuit measures the distance covered during a walk. Hardware is located in a small box slipped in pants` pocket and the display is conceived in the following manner: the leftmost display D2 (the most significant digit) shows 0 to 9 Km. and its dot is....
-
-
-
T1 and XTal have formed an oscillator. C1 and C2 are voltage divider for oscillator. if the XTal is safe, the oscillator will work well and its output voltage will be rectified by C3, C4, D1 and D2, then T2 will run and LED will light. The circuit is....
-
-
This circuit uses the popular and easy to find LM3914 IC. This IC is very simple to drive, needs no voltage regulators (it has a built in voltage regulator) and can be powered from almost every source. When the test button is pressed, the Car battery voltage....
-
This 3 channel 15 LED spectrum analyzer is the perfect addition to any audio amp project. It produces fantastic displays on three LED bars that can be individually adjusted for any particular frequency range. The circuit will take line level output from most....
-
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....
-
a programmable clock timer circuit that uses individual LEDs to indicate hours and minutes. 12 LEDs can be arranged in a circle to represent the 12 hours of a clock face and an additional 12 LEDs can be arranged in an outer circle to indicate 5 minute....
-
The 30 watt amplifier schematic shown below provides an appropriate power boost with an input of 4 watt up to 6 watts. The circuit is designed to cover 88-108MHz FM Broadcast Band. However, the circuit is very stable at my place and provides a clean-output....
-
This is the schematic for an FM transmitter with 3 to 3. 5 W output power that can be used between 90 and 110 MHz. Although the stability isn`t so bad, a PLL can be used on this circuit. This is a circuit that I`ve build a few years ago for a friend, who....
-
-
-
This circuit is an Electronic Locker. It is controlled by a switches combination (by a code). There is a switch matrix on the door of the locker. This one is a unit of switches connected into 4 arranged of 4 columns for a total of eight terminals. When we....
-
The sound produced imitates the rise and fall of an American police siren. When first switched on the 10u capacitors is discharged and both transistors are off. When the push button switch is pressed to 10u capacitor will charge via the 22k resistor. This....
-
Many sites doesn`t provide circuits driving these transformers, they simply say that they are bad. I don`t agree. In fact I built this circuit. I spent a lot of time for finding resonant frequency (around 15Khz) and duty cycle. These transformers best work at..
-
-
This circuit uses an MC3392 low side protected switch and an MC1455 timing circuit to form an automotive instrumentation panel lamp dimmer control. The brightness of incandescent lamps can be varied by Pulse Width Modulating the input of the MC3392. The....
-
The RF engineer sometimes has to look for an instrument that will check a low frequency quartz crystal unit reliably and rapidly. This is a difficult piece of equipment to find and the engineer often has to consult an electronic circuits handbook for the....
-
-
-
-
-
Any type of flashing light on the main brake lights is prohibited and illegal in most states of the U. S. A. I`m verifying for the same here in Canada. In the mean time, use this circuit at your own risk and be aware that the possibility exists to be stopped....
-
-
-
How to connect up some lights so that when the phone rings, they flash. This is very useful in a situation were there is lots of noise and it is impossable to hear the phone, such as a workshop. Here is such a device. The ring detect part of this circuit....
-
This is a fun and useful circuit for demonstrating high frequency high voltge. It can produce up to about 30KV, depending on the transformer used. It is cheap and easy to make, thanks to the standard TV flyback transformer used. It can power LASERS (although....
-
-
This little circuit can be used to dim lights up to about 350 watts. It uses a simple, standard TRIAC circuit that, in my expirience, generates very little heat. Please note that this circuit cannot be used with fluorescent lights...
-
This circuit enables observation of movement between other stroboscopes. Generation of rectangular signal is based on NE555. This circuit requires a low power supply that is made from a simple transformer TR1, traditional rectifier bridge and zener diode.....
-
This is a very good integrated circuit. There is no need for any external glue logic to drive the circuit, there is only 2 pins to drive the motor, one for controlling the direction and the other to trigger the stepping pulses. It provides a very compact....
-
A Variable DC Power Supply is one of the most useful tools on the electronics hobbyist`s workbench. This circuit is not an absolute novelty, but it`s simple, reliable, "rugged" and short-proof, featuring variable voltage up to 24V and variable current....
-
An ordinary energy system comprises a generator and motor (common view), and can be completed with an electric current feedback as shown here in electrical circuit (a) In case (a), the system once started, will slow down and stop because of friction,....
-
-
IC2 is wired as a low frequency astable with a cycle period of about 6 seconds. The slowly varying ramp waveform at C1 is fed to PNP emitter follower Q1, and is then used to frequency modulate alarm generator IC1 via R6. IC1 has a natural center frequency of....
-
Usually a single telephone is connected to a telephone line. If another telephone is required at some distance, a parallel line is taken for connecting the other telephone. In this simple parallel line operation, the main problem is loss of privacy besides....
-
This circuit is able to handle nine independent telephones (using a single telephone line pair) located at nine different locations, say, up to a distance of 100m from each other, for receiving and making outgoing calls, while maintaining conversation....
-
The interval between rings can be lengthened or shortened by varying the value of the 1 Meg resistor. The 70 volt/ 30 Hz ring voltage is produced from the 120 volt side of a small 12. 6 VAC power transformer (Radio Shack 273-1365). Both capacitors connected....
-
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....
-
Wind 6 turns of solid wire on a pen or pencil that is just under 1/2 inch in diameter. Remove the wire from the pencil and spread the winding to make a length of 3/4 inch. Solder C2 somewhere near the middle of the coil...
-
This is a very simple RF transmitter circuit that consists of the Holtek HT-12E encoder chip and AM 418MHZ-transmitter module ( WZ-X01 ). Using the hybrid RF xmit/receive modules make building the RF remote control a lot easy. The transmitter can be powered....
-
How to use your existing infrared transmitter from any room in the house. The principal is really pretty simple, and it works better than you would think. This is a "very handy" little project. With this gadget you can control anything from pretty much....
-
This circuit came from a 14 Watt Commercial Electric spiral bulb from Home Depot. In fact, I drew it in that way because it was layed out very well, so much credit should go to Sam Goldwasser. It is a rather interesting oscillator circuit which I will....
-
This circuit used to come as a kit from a surplus supplier, but probably isn`t available anymore. It shows a few novel concepts such as using a 555 as a pulse width modulator (PWM), and series/parallel camera flash transformers. WARNING: This circuit is....
-
-
This circuit provides you with wireless audio and visual transmission to a TV. The TV acts as a receiver, eliminating the need to buy a separate monitor. You can also hook it up to a VCR or CCD Camera, and even set up a remote CCTV security system! Q3, VC1,....
-
The 555 timer will put out positive pulses. The pulse width is inversely proportional to the difference in voltage between the voltage at "ANALOG IN" and the voltage of the 4. 7uF capacitor(let`s say 2. 5 volts). To calibrate this circuit, hook it up to a....
-
Each audio/video output can be switched to any of the 8 inputs, separately. One module drives one audio/video output and has a 34-pin connector to plug into the system interface. You can use video OPA-s on the 4051 output instead. Note that you can get full....
-
-
-
-
-
-
The current task is to design the schematic layout, design the PCB layout, and generate the. contractor with RF schematic design and PCB layout experience Please review the block diagram in the attached. antenna will be connected to the RFOUT coax and an RF....
-
-
-
-
A single chip circuit for Echo & Delay. If you can modify a mic mixer circuit, you can easyly use this circuit with your microphone. PT2399 is an echo audio processor IC utilizing CMOS Technology which is equipped with ADC and DAC, high sampling frequency....
-
-
A rear wiper/washer similar what every SUV on the road has. this kit has the motor mounting through the glass, which the end users cannot do since the glass is tempered. The truck cap manufacturers can have the glass drilled appropriately, before tempering.....
-
Hardware implementations of spiking neurons can be extremely useful for a large variety of applications, ranging from high-speed modeling of large-scale neural systems to real-time behaving systems, to bidirectional brain machine interfaces. The specific....
-
The circuitry of the ZXInterface2 is very simple and is comprised of a single custom made IC which performs address decoding for the twin joystick interface. The ROM cartridge socket simply exposes signals already available from the Spectrum`s edge....
-
The features available via the keypad are mentioned in the Spectrum128 Introduction Manual that was included with every machine sold. The service manual for the Spectrum128 is aimed at repair technicians and describes the circuitry and communications....
-
The keypad circuitry is based around a PIC1652 microcontroller that was manufactured by General Instruments. The PIC1652 is an 8-bit microcontroller with RISC-like features and has a 33 single-word instruction set. It supports direct, indirect and relative....
-
-
-
Supports LCD Module (16x2 HD44780) Includes AVR Micro ATMEGA168 programmed with demo/test code. Top Quality US made PCB (w/Solder mask, Plated through holes, RoHS compliant) Designed by a long term amateur radio operator(N3ZI) and engineer (BSEE)....
-
An IDE interface board and I`m currently working on the driver software to support reading/writing on a hard drive under my OS-X 2. 0 RTOS. An assembled IDE interface board is shown below. Download pcb. zip which contains the schematic and PCB layout files....
-
The RT320 and RT321 Clansman HF sets are designed for Upper Side Band (USB) operation only. This conflicts with the Amateur radio convention which is to use LSB on bands below 10MHz. In both radios the IF used for SSB generation is 1. 7500 MHz and there is a....
-
The RA17C18 is modified version of the RA17C12, having a delay compensated IF amplifier and an additional IF output. It is a North American version of the RA17, ie. , it uses all BNC and SO239 connectors, all fasteners have unified threads, and the harmonic....
-
A modification to David Knight`s linear detector circuit. I wanted to build a "hi-fidelity" AM receiver and needed an ultra-linear AM detector for it. Here is the circuit I came up with: Note that I eliminated the meter circuit, and removed a lot of the....
-
-
The circuit is presented as a starting point - there will be some experimentation needed for each individual case. For the popular microwave bands the LOs are usually generated from overtone crystal oscillators followed by multipliers, with the following....
-
The Comtech has become the de facto standard now for those entering the Amateur TV scene. Sadly the production may be coming to an end with the lower demand for analog tuners and the ICs used becoming obsolete. With the demise of the G1MFG website there is....
-
-
-
The clock shows time in 5 minute intervals. The hour and minute can be set. There is no alarm or any AM/PM indicator. For the clock face I used a 2 pieces of lenolium glued together to increase thickness. (A couple of floor tiles would work as well. ) The....