Top Circuits Page 119
- Page 119
-
In conventional triangular-wave oscillators, hysteresis from positive feedback in the Schmitt trigger determines the voltage levels and amplitude of the triangular waves. With this topology, it`s difficult to independently vary the voltage levels and....
-
-
The versatile circuit shown can be used to realize several different circuit functions ”an astable multivibrator, a monostable multivibrator, a switch debouncer, or a frequency discriminator ( Fig. 1 ). Inverters U1a and U1b are connected as a latch. When....
-
Micro or analog? These days it is getting harder to choose. The 555 timer was the benchmark of flexibility. How does it fare today?...
-
This article describes a dc-ac inverter circuit that generates the high-voltage ac signal required to drive an electroluminescent (EL) panel. It`s based on the Sipex SP4425 EL lamp-driver IC..
-
-
The FTDI DLP-USB245M is a USB-to FIFO interface module that simplifies the control of multiple steppers by a PC..
-
-
-
Software-defined radios (SDRs) are used in all areas of communications including ham radio and SWL..
-
Due to their low cost, stepping-motor controllers are often chosen over full-blown, software-driven controllers for a number of applications. However, stepping motors provide rather low torque at high speeds, thus they usually require a starting ramp to....
-
Combining armature resistance cancellation (via positive current feedback) with a motion-reversing H-bridge circuit topology offers a new twist in dc servo motor speed control..
-
The aim of this circuit is to keep the permanent magnet dc motor running at a constant speed, set externally. To do this, the current through, and the voltage across, the brushes of the motor are monitored..
-
-
Design A Low-Cost 4- To 20-mA Receiver Circuit For Control Loops | analog-to-digital converter (ADC)...
-
This design idea explains how to develop a water sensor circuit that can monitor upper and lower water levels..
-
This Idea for Design describes a 12-V dc to 5-V dc (±5%) switched-mode power supply (SMPS). The supply uses a 12-V input from an array of four 3-V dc, 40-mA solar cells connected in series..
-
IR`s Wibowa Chou explains the advantages of 4th-generation IGBTs over MOSFETS with a practical solar inverter application...
-
A common problem in crystal sinusoidal oscillators is the excitation of unwanted modes of the quartz crystal that degrade the spectral purity of the oscillator. This problem is significant in overtone crystals, particularly if the oscillator is intended for....
-
Ambient light is increasingly being used as a source of energy. To help designers of such systems, this circuit accurately measures ambient light intensity over four decades of measurement. The design is highly cost effective and, with the sensor mounted in....
-
This voltage-booster circuit for driving one or more white LEDs uses a 555 timer as its main element ( see the figure ). The timer, IC1, functions as a resettable astable multivibrator where R1, R2, and C2 are the timing components. When the supply voltage,....
-
The circuit illustrated here comes to the rescue by sniffing out defective bulbs by capacitively sensing the electric fields they produce ( see the figure ). To understand how it works, consider a string of bulbs with an opencircuited filament, labeled in....
-
The circuit shown flashes the LED briefly (to get your attention) and stays on as long as the power is on ( Fig. 1 ). The venerable 555 timer IC can be put to use in this type of application. The circuit is a standard astable multivibrator with resistors RA,....
-
The 1-Wire Net, or MicroLAN (by Maxim-Dallas), is a simple way to connect slow devices (such as sensors, relay drivers, switches, and so on) using simple components. These components contain the 1-Wire protocol handler, some type of interface to the external....
-
It uses standard components, gives a good sine wave and is fairly immune to the type of op ampit is designed around. It can, however, be misunderstood, and over simplifications as to its operation can leave the designer thinking that it is not as well....
-
Cable and xDSL modems are experiencing increasing popularity. For this reason, many designs are now required to interface with existing telephones at the subscriber`s location. The subscriber line interface circuit (SLIC) within the modem has the additional....
-
Consider the need to vary two voltages, V1 and V2, by an equal percentage of their ranges (V1MAX - V1MIN) and (V2MAX - V2MIN), with V1MAX, V1MIN, V2MAX, and V2MIN independent of each other. The first idea that comes to mind is to use ganged potentiometers....
-
Fast rise-time high-voltage pulses have many uses ranging from EMC testing to device characterization. The simple, low-cost circuit described here deals with the latter. It`s able to generate 0- to 1000-V pulses with currents up to 50 A, and a rise time of....
-
By adding a discharge path to the upper MOSFET of a cascode circuit, the unavoidable Miller effect is greatly reduced and the PFC performance of a power supply`s front end can be improved..
-
-
Medical and industrial applications often require galvanic isolation of 2500 V ac or higher for the safety of patients and equipment operators. The isolation barrier conveys not only power to the sensing element, but also data to or from that element. Each....
-
Current-control switching-mode power supplies (SMPS) are gaining in popularity because they allow pulse-by-pulse current control and monitoring, making them more reliable and robust than their voltage-controlled counterparts. Current control also eliminates....
-
Although analog and digital controllers may appear vastly different, their principles of operation are usually quite similar. Therefore, popular analog tools like Spice can still be used to benefit common digital proportional-integral controllers through....
-
This low-cost function generator, based on the Maxim MAX038 high-frequency waveform generator, produces sine, triangle, and square waves from under 1 Hz to over 20 MHz..
-
Use the Maxim MAX292 switched-capacitor filter IC to round a square wave into a sine wave; the circuit`s frequency range is between 5.2282 Hz and 8928.6 Hz when the microcontroller is operating at a 16-MHz clock frequency..
-
The basic technique is the same like the last lesson except fact that we have added a counter which counts between 0000 and 9999. Our counter increments with 1 second delay. /* ` * ` Lesson nr. 12: ` Multiplexed 7Segment as counter mode ` Done by: `....
-
In this Lesson, we will make a digital temperature meter using DS18B20. The connection between temperature sensor and microcontroller will be done through a single wire. This is advantage of the temperature sensor model. The temperature value will be....
-
The communication technique with the LCD is the same like the last lesson, and for the current experiment we have added a counter which counts between 0000 and 9999. Our counter increments with 1 second delay. /* ` * ` Lesson nr. 16: ` Alphanumeric LCD as....
-
Here is a `beeper` circuit employing two 555 ICs. It can be used in various circuits (having supply voltage of 5 to-15V DC) that require an alarm or a `beeping` signal. IC1 is connected in astable mode in the circuit in such a way that squarewave output at....
-
Today, most telephone equipment use a DTMF receiver IC. One common DTMF receiver IC is the Motorola MT8870 that is widely used in electronic communications circuits. The MT8870 isan 18-pin IC. It is used in telephones and a variety of other applications.....
-
-
-
-
-
-
-
-
-
-
-
You can start to set your Square Wave Generator up using 555 timer IC through the circuit shown above. Find it match with the pinout of 555 timer IC. The osciloscope is then connected to the output of 555 timer IC in order to view the square wave. From the....
-
This standalone digital thermometer controls the temperature of a device according to its requirement. It also displays the temperature on four 7-segment displays in the range of 55 to +125 °C. At the heart of the circuit is the microcontroller AT89S52,....
-
Designing a simple and yet functional Line Follower Robot (LFR) is always a fascinating and challenging subject to be learned, the LFR actually could be implemented in many ways start from a simple two transistors to a sophisticated PID (Proportional,....
-
average vending machines are commonplace at railway stations, airports, fast-food restaurants and even in companies. Press a switch and the machine delivers a cup of your favorite drink. This looks quite a simple operation but has a very complex logic behind....
-
This design is based on the 18 Watt Audio Amplifier, and was developed mainly to satisfy the requests of correspondents unable to locate the TLE2141C chip. It uses the widespread NE5532 Dual IC but, obviously, its power output will be comprised in the 9. 5 -....
-
This design adopts a well established circuit topology for the power amplifier, using a single-rail supply of about 60V and capacitor-coupling for the speaker(s). The advantages for a guitar amplifier are the very simple circuitry, even for comparatively....
-
This design adopts a well established circuit topology for the power amplifier, using a single-rail supply of about 60V and capacitor-coupling for the speaker(s). The advantages for a guitar amplifier are the very simple circuitry, even for comparatively....
-
-
As a keen cyclist I am always looking for ways to be seen at night. I wanted something that was a novelty and would catch the motorists eye. So looking around at my fellow cyclists rear lights, I came up with the idea of `NITE-RIDER`. NINE extra bright LED`s....
-
This page features a circuit that has twenty open collector outputs that turn on one at a time in a continuous, unidirectional loop sequence. The circuit uses the 74LSxx family of TTL integrated logic devices. The circuits are designed to drive light....
-
Manual buzzers used for quiz competitions in schools and colleges create a lot of confusion in identifying the first respondent. Although there are circuits using PCs and discrete ICs, they are either too expensive or limited to only a few number of players.....
-
ADC (Analogto digital converter) forms a very essential part in many embedded projects and this article is about interfacing an ADC to 8051 embedded controller. ADC 0804 is the ADC used here and before going through the interfacing procedure, we must neatly....
-
A three digit contact less digital tachometer using 8051 microcontroller which can be used for measuring the revolutions/second of a rotating wheel, disc, shaft or anything like that is introduced in this project. The tachometer can measure up to a maximum....
-
The non-sinusoidal waveform generators are also called relaxation oscillators. The op-amp relaxation oscillator shown in figure is a square wave generator. In general, square waves are relatively easy to produce. Like the UJT relaxation oscillator, the....
-
This super simple design of aninvertercircuit does not limit it in any way from providing a high output power and an efficiency of a good 75%. Learn how to build aninverterthat will satisfy most of your power requirement at quite an affordable cost. The....
-
A lot of FM transmitter circuits have been already published here. This just another one, a simple two transistor FM transmitter. The first stage of the circuit is a preamplifier stage based on transistor Q1. This is a collector to base biased amplifier....
-
A simple ultrasonic range finder using 8051 microcontroller is presented in this article. This ultrasonic rangefinder can measure distances up to 2. 5 meters at an accuracy of 1 centi meter. AT89s51 microcontroller and the ultrasonic transducer module....
-
The transmitter part of the circuit is build around IC1(NE 555). The IC1 is wired as an astable multi vibrator operating at 40KHz. The output of IC1 is amplifier the complementary pair of transistors ( Q1 & Q2) and transmitted by the ultrasonic transmitter....
-
A water level controller based using 8051 is shown in this article. A lot of water level controller projects have been published in this website but the is the first one based on a microcontroller. This water level controller monitors the level of the over....
-
This document describes a basic circuit that can be used to power high impedance, high voltage, low current devices such as EL backlights and fluorescent tubes. This project got its genesis when I needed a simple, yet flexible inverter circuit for an EL....
-
Did it ever occur to you that an array of white LEDs can be used as a small lamp for the living room If not, read on. LED lamps are available ready-made, look exactly the same as standard halogen lamps and can be fitted in a standard 230-V light fitting. We....
-
Here is a simple but inexpensive inverter for a small soldering iron (25W, 35W, etc) In the absence of mains supply. It uses eight transistors and a few resistors and capacitors. Transistors Q1 and Q2 (each BC547) form an astable multivibrator that produces....
-
The following picture shows theYamaha 175Wiring Diagram(CT2 and CT3 model) andElectrical SystemSchematic. Herein you get detail information regarding the interconnection and wiring between electrical parts and components of the motorcycle such as battery,....
-
-
-
This project based on Atmel AT89C52 and Dallas real-timeclock (RTC) chip DS12887 can be used to control and remotely program the switching operation of 24 electrically operated devices. The devices can be switched on/off at precise times repeatedly every....
-
-
Personal Radar System using PIC MIcrocontroller PIC18f452 is a microcontroller hobby project. The circuit diagram of radar is attached here below seemed a little bit simple schematic but you need careful reading of PIC18f452 radar circuit to avoid any....
-
With this circuit you can build a very small tracking transmitter that can be tracked using a FM broadcast band radio receiver. The transmitter can be powered from any 1.5V volt battery or power supply. Transmitter has a range up to 1 mile depending on....
-
There is a great deal of old amateur gear which many amateurs have decided to restore and bring back to life. While much of the early amateur transceivers work just fine they usually lack a digital readout and must rely on analog dials for tuning. The....
-
This is a 6m band transmitter RF power amplifier (50 MHz) with 100W output. It used with my FT-736R and drive from 10W for the 6m SSB DX. The Building information comes from Japan CQ Magazine. The Toshiba RF bipolar power transistor is used in it. If you....
-
This is a universal 1 Watt RF class C amplifier that is ideally suited for low power FM transmitters. Input should be at least 100mW to achieve 1W output. It is recommended to enclose the amplifier in a metal case. Build your own Accurate LC Meter....
-
A very good 1 watt fm transmitter circuit, very easy to build circuit. It has 4 transistors, one is a very stable oscillator, followed by a buffer stage to prevent frequency variation when you adjust the transmitter. Next is a resonance stage and the final....
-
Long range, very stable, harmonic free, FM transmitter circuit which can be used for FM frequencies between 88 and 108 MHz. With good antenna transmitter can cover 5km range. It has a very stable oscillator because it uses LM7809 voltage regulator which is a....
-
In this project, you will make a simple 3-stage low-power broadcast-type circuit, using a crystal oscillator integrated circuit and an a collector modulated AM oscillator with amplifier. You can connect the circuit to the an electred microphone or amplified....
-
This 2 Watt FM transmitter will provide 10km range in good weather conditions. Use dipole antenna for maximum range. Transmitter can be tuned between 88-108 MHz with c5. BB204 could be replaced with conventional led (big) with reverse bias (no light given in....
-
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....
-
This little broadcast FM transmitter has 500mW of RF output power and runs of 12-15V battery or power supply. DC whose signal modulated by FM using four transistors. Transmitter includes four transmitter stages and draws around 100-150mA of current. Using....
-
60MHz Frequency Meter / Counter measures frequency from 10Hz to 60MHz with 10Hz resolution. It is extremely useful bench test equipment for testing and measuring frequency of oscillators, transmitters, radio receivers, function generators, crystals, etc.....
-
Here is a circuit for simulating breathing / pulsing LED with the 555 timer chip. It became very popular and i received many comments and emails with people that made this circuit and worked fine, as well as comments with people that had troubles converting....
-
This Voltmeter Ammeter was designed to measure output voltage of 0-70V / 0-500V with 100mV resolution and 0-10A or more current with 10mA resolution. It is a perfect addition to any DIY laboratory power supply, battery chargers and other electronic projects....
-
Rectifier bridge voltage. See U2 element you used data sheet to know about maximum voltage it can work properly. On the other hand the minimum voltage on that pin mustn`t drop bellow c. a. 9V, or 6. 5V if low drop type U2 and U3 voltage regulators were used.....
-
This is an excellent Hi-Fi Stereo PLL FM Transmitter, the audio source can be the computer, sound card, game consoles, CD, DVD, MP3, stereo mixer for stereo audio signal modulated emission transmission, the board also contains two mic amplifier, with the....
-
FT232RL USB to Serial UART (TTL) Adapter is a simple and inexpensive way to connect PIC, AVR or ATMEGA MCUs to a PC or Mac via USB connection. FT232RL is an impressive chip because it implements full v2. 0 USB protocol, needs no external crystal, has....
-
This digital voltmeter is ideal to use for measuring the output voltage of your DC power supply. It includes a 3. 5-digit LED display with a negative voltage indicator. It measures DC voltages from 0 to 199. 9V with a resolution of 0. 1V. The voltmeter is....
-
This is a high fidelity external USB Soundcard / USB Headphones project that can be built for your PC or Mac. It is based on the latest PCM2706 IC which functions as a high quality, crystal clear 16-BIT Stereo DAC. It is a single chip digital-to-analog....
-
This Phone FM transmitter connects in series to your telephone line and transmits the telephone conversation over the FM band when you pick up the telephone handset. Transmitted signal can be tuned by any FM receiver. The circuit includes an "On Air" LED....
-
AM radio built around 555 timer chip. The only active device (silicon, germanium, or otherwise) is the LM555. The tuning is accomplished with an inductor and a capacitor, and the LM555 acts as an AM demodulator and class-D power amplifier to drive the....
-
Automatic battery charger automatically starts the charging procedure when battery voltage drops below a certain predefined value and stops after the voltage has risen above the maximum allowed value. Setup can`t be easier, just connect two alligator clips....
-
This is simple to build AVR programmer for Atmel microcontrollers from AVR family. The microcontrollers must support serial programming. AVR programmer is connected to a PC through the RS232 serial interface and can be used with the PonyProg or Avrdude....
-
This simple tone control (bass & treble control) can be used in may audio applications. It can be added to amplifiers, used as a stand alone control module, or even built into new and exciting instruments. It uses NE5532 IC but other ICs such as LF353 or....
-
This is a simple video transmitter that can transmit as far as 50 meters. This video transmitter can be used with the camera or other video sources. You can view them on VHF channel analog TV. Supply voltage to the video transmitter can use 9V battery.....
-
Not thrilled with how a computer soundcard drove my 32ohm headphones so I decided to build myself class-A mosfet headphone amplifier. As with most of my projects, the goal was to keep it simple, keep cost down and try use some salvaged parts. This is a....
In conventional triangular-wave oscillators, hysteresis from positive feedback in the Schmitt trigger determines the voltage levels and amplitude of the triangular waves. With this topology, it`s difficult to independently vary the voltage levels and....
Micro or analog? These days it is getting harder to choose. The 555 timer was the benchmark of flexibility. How does it fare today?...
Software-defined radios (SDRs) are used in all areas of communications including ham radio and SWL..
Due to their low cost, stepping-motor controllers are often chosen over full-blown, software-driven controllers for a number of applications. However, stepping motors provide rather low torque at high speeds, thus they usually require a starting ramp to....
Design A Low-Cost 4- To 20-mA Receiver Circuit For Control Loops | analog-to-digital converter (ADC)...
This design idea explains how to develop a water sensor circuit that can monitor upper and lower water levels..
Ambient light is increasingly being used as a source of energy. To help designers of such systems, this circuit accurately measures ambient light intensity over four decades of measurement. The design is highly cost effective and, with the sensor mounted in....
It uses standard components, gives a good sine wave and is fairly immune to the type of op ampit is designed around. It can, however, be misunderstood, and over simplifications as to its operation can leave the designer thinking that it is not as well....
By adding a discharge path to the upper MOSFET of a cascode circuit, the unavoidable Miller effect is greatly reduced and the PFC performance of a power supply`s front end can be improved..
Current-control switching-mode power supplies (SMPS) are gaining in popularity because they allow pulse-by-pulse current control and monitoring, making them more reliable and robust than their voltage-controlled counterparts. Current control also eliminates....
The basic technique is the same like the last lesson except fact that we have added a counter which counts between 0000 and 9999. Our counter increments with 1 second delay. /* ` * ` Lesson nr. 12: ` Multiplexed 7Segment as counter mode ` Done by: `....
In this Lesson, we will make a digital temperature meter using DS18B20. The connection between temperature sensor and microcontroller will be done through a single wire. This is advantage of the temperature sensor model. The temperature value will be....
The communication technique with the LCD is the same like the last lesson, and for the current experiment we have added a counter which counts between 0000 and 9999. Our counter increments with 1 second delay. /* ` * ` Lesson nr. 16: ` Alphanumeric LCD as....
Here is a `beeper` circuit employing two 555 ICs. It can be used in various circuits (having supply voltage of 5 to-15V DC) that require an alarm or a `beeping` signal. IC1 is connected in astable mode in the circuit in such a way that squarewave output at....
Today, most telephone equipment use a DTMF receiver IC. One common DTMF receiver IC is the Motorola MT8870 that is widely used in electronic communications circuits. The MT8870 isan 18-pin IC. It is used in telephones and a variety of other applications.....
You can start to set your Square Wave Generator up using 555 timer IC through the circuit shown above. Find it match with the pinout of 555 timer IC. The osciloscope is then connected to the output of 555 timer IC in order to view the square wave. From the....
This standalone digital thermometer controls the temperature of a device according to its requirement. It also displays the temperature on four 7-segment displays in the range of 55 to +125 °C. At the heart of the circuit is the microcontroller AT89S52,....
Designing a simple and yet functional Line Follower Robot (LFR) is always a fascinating and challenging subject to be learned, the LFR actually could be implemented in many ways start from a simple two transistors to a sophisticated PID (Proportional,....
average vending machines are commonplace at railway stations, airports, fast-food restaurants and even in companies. Press a switch and the machine delivers a cup of your favorite drink. This looks quite a simple operation but has a very complex logic behind....
This design is based on the 18 Watt Audio Amplifier, and was developed mainly to satisfy the requests of correspondents unable to locate the TLE2141C chip. It uses the widespread NE5532 Dual IC but, obviously, its power output will be comprised in the 9. 5 -....
This design adopts a well established circuit topology for the power amplifier, using a single-rail supply of about 60V and capacitor-coupling for the speaker(s). The advantages for a guitar amplifier are the very simple circuitry, even for comparatively....
As a keen cyclist I am always looking for ways to be seen at night. I wanted something that was a novelty and would catch the motorists eye. So looking around at my fellow cyclists rear lights, I came up with the idea of `NITE-RIDER`. NINE extra bright LED`s....
This page features a circuit that has twenty open collector outputs that turn on one at a time in a continuous, unidirectional loop sequence. The circuit uses the 74LSxx family of TTL integrated logic devices. The circuits are designed to drive light....
Manual buzzers used for quiz competitions in schools and colleges create a lot of confusion in identifying the first respondent. Although there are circuits using PCs and discrete ICs, they are either too expensive or limited to only a few number of players.....
ADC (Analogto digital converter) forms a very essential part in many embedded projects and this article is about interfacing an ADC to 8051 embedded controller. ADC 0804 is the ADC used here and before going through the interfacing procedure, we must neatly....
A three digit contact less digital tachometer using 8051 microcontroller which can be used for measuring the revolutions/second of a rotating wheel, disc, shaft or anything like that is introduced in this project. The tachometer can measure up to a maximum....
The non-sinusoidal waveform generators are also called relaxation oscillators. The op-amp relaxation oscillator shown in figure is a square wave generator. In general, square waves are relatively easy to produce. Like the UJT relaxation oscillator, the....
This super simple design of aninvertercircuit does not limit it in any way from providing a high output power and an efficiency of a good 75%. Learn how to build aninverterthat will satisfy most of your power requirement at quite an affordable cost. The....
A lot of FM transmitter circuits have been already published here. This just another one, a simple two transistor FM transmitter. The first stage of the circuit is a preamplifier stage based on transistor Q1. This is a collector to base biased amplifier....
A simple ultrasonic range finder using 8051 microcontroller is presented in this article. This ultrasonic rangefinder can measure distances up to 2. 5 meters at an accuracy of 1 centi meter. AT89s51 microcontroller and the ultrasonic transducer module....
The transmitter part of the circuit is build around IC1(NE 555). The IC1 is wired as an astable multi vibrator operating at 40KHz. The output of IC1 is amplifier the complementary pair of transistors ( Q1 & Q2) and transmitted by the ultrasonic transmitter....
A water level controller based using 8051 is shown in this article. A lot of water level controller projects have been published in this website but the is the first one based on a microcontroller. This water level controller monitors the level of the over....
This document describes a basic circuit that can be used to power high impedance, high voltage, low current devices such as EL backlights and fluorescent tubes. This project got its genesis when I needed a simple, yet flexible inverter circuit for an EL....
Did it ever occur to you that an array of white LEDs can be used as a small lamp for the living room If not, read on. LED lamps are available ready-made, look exactly the same as standard halogen lamps and can be fitted in a standard 230-V light fitting. We....
Here is a simple but inexpensive inverter for a small soldering iron (25W, 35W, etc) In the absence of mains supply. It uses eight transistors and a few resistors and capacitors. Transistors Q1 and Q2 (each BC547) form an astable multivibrator that produces....
The following picture shows theYamaha 175Wiring Diagram(CT2 and CT3 model) andElectrical SystemSchematic. Herein you get detail information regarding the interconnection and wiring between electrical parts and components of the motorcycle such as battery,....
This project based on Atmel AT89C52 and Dallas real-timeclock (RTC) chip DS12887 can be used to control and remotely program the switching operation of 24 electrically operated devices. The devices can be switched on/off at precise times repeatedly every....
Personal Radar System using PIC MIcrocontroller PIC18f452 is a microcontroller hobby project. The circuit diagram of radar is attached here below seemed a little bit simple schematic but you need careful reading of PIC18f452 radar circuit to avoid any....
With this circuit you can build a very small tracking transmitter that can be tracked using a FM broadcast band radio receiver. The transmitter can be powered from any 1.5V volt battery or power supply. Transmitter has a range up to 1 mile depending on....
There is a great deal of old amateur gear which many amateurs have decided to restore and bring back to life. While much of the early amateur transceivers work just fine they usually lack a digital readout and must rely on analog dials for tuning. The....
This is a 6m band transmitter RF power amplifier (50 MHz) with 100W output. It used with my FT-736R and drive from 10W for the 6m SSB DX. The Building information comes from Japan CQ Magazine. The Toshiba RF bipolar power transistor is used in it. If you....
This is a universal 1 Watt RF class C amplifier that is ideally suited for low power FM transmitters. Input should be at least 100mW to achieve 1W output. It is recommended to enclose the amplifier in a metal case. Build your own Accurate LC Meter....
A very good 1 watt fm transmitter circuit, very easy to build circuit. It has 4 transistors, one is a very stable oscillator, followed by a buffer stage to prevent frequency variation when you adjust the transmitter. Next is a resonance stage and the final....
Long range, very stable, harmonic free, FM transmitter circuit which can be used for FM frequencies between 88 and 108 MHz. With good antenna transmitter can cover 5km range. It has a very stable oscillator because it uses LM7809 voltage regulator which is a....
In this project, you will make a simple 3-stage low-power broadcast-type circuit, using a crystal oscillator integrated circuit and an a collector modulated AM oscillator with amplifier. You can connect the circuit to the an electred microphone or amplified....
This 2 Watt FM transmitter will provide 10km range in good weather conditions. Use dipole antenna for maximum range. Transmitter can be tuned between 88-108 MHz with c5. BB204 could be replaced with conventional led (big) with reverse bias (no light given in....
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....
This little broadcast FM transmitter has 500mW of RF output power and runs of 12-15V battery or power supply. DC whose signal modulated by FM using four transistors. Transmitter includes four transmitter stages and draws around 100-150mA of current. Using....
60MHz Frequency Meter / Counter measures frequency from 10Hz to 60MHz with 10Hz resolution. It is extremely useful bench test equipment for testing and measuring frequency of oscillators, transmitters, radio receivers, function generators, crystals, etc.....
Here is a circuit for simulating breathing / pulsing LED with the 555 timer chip. It became very popular and i received many comments and emails with people that made this circuit and worked fine, as well as comments with people that had troubles converting....
This Voltmeter Ammeter was designed to measure output voltage of 0-70V / 0-500V with 100mV resolution and 0-10A or more current with 10mA resolution. It is a perfect addition to any DIY laboratory power supply, battery chargers and other electronic projects....
Rectifier bridge voltage. See U2 element you used data sheet to know about maximum voltage it can work properly. On the other hand the minimum voltage on that pin mustn`t drop bellow c. a. 9V, or 6. 5V if low drop type U2 and U3 voltage regulators were used.....
This is an excellent Hi-Fi Stereo PLL FM Transmitter, the audio source can be the computer, sound card, game consoles, CD, DVD, MP3, stereo mixer for stereo audio signal modulated emission transmission, the board also contains two mic amplifier, with the....
FT232RL USB to Serial UART (TTL) Adapter is a simple and inexpensive way to connect PIC, AVR or ATMEGA MCUs to a PC or Mac via USB connection. FT232RL is an impressive chip because it implements full v2. 0 USB protocol, needs no external crystal, has....
This digital voltmeter is ideal to use for measuring the output voltage of your DC power supply. It includes a 3. 5-digit LED display with a negative voltage indicator. It measures DC voltages from 0 to 199. 9V with a resolution of 0. 1V. The voltmeter is....
This is a high fidelity external USB Soundcard / USB Headphones project that can be built for your PC or Mac. It is based on the latest PCM2706 IC which functions as a high quality, crystal clear 16-BIT Stereo DAC. It is a single chip digital-to-analog....
This Phone FM transmitter connects in series to your telephone line and transmits the telephone conversation over the FM band when you pick up the telephone handset. Transmitted signal can be tuned by any FM receiver. The circuit includes an "On Air" LED....
AM radio built around 555 timer chip. The only active device (silicon, germanium, or otherwise) is the LM555. The tuning is accomplished with an inductor and a capacitor, and the LM555 acts as an AM demodulator and class-D power amplifier to drive the....
Automatic battery charger automatically starts the charging procedure when battery voltage drops below a certain predefined value and stops after the voltage has risen above the maximum allowed value. Setup can`t be easier, just connect two alligator clips....
This is simple to build AVR programmer for Atmel microcontrollers from AVR family. The microcontrollers must support serial programming. AVR programmer is connected to a PC through the RS232 serial interface and can be used with the PonyProg or Avrdude....
This simple tone control (bass & treble control) can be used in may audio applications. It can be added to amplifiers, used as a stand alone control module, or even built into new and exciting instruments. It uses NE5532 IC but other ICs such as LF353 or....
This is a simple video transmitter that can transmit as far as 50 meters. This video transmitter can be used with the camera or other video sources. You can view them on VHF channel analog TV. Supply voltage to the video transmitter can use 9V battery.....
Not thrilled with how a computer soundcard drove my 32ohm headphones so I decided to build myself class-A mosfet headphone amplifier. As with most of my projects, the goal was to keep it simple, keep cost down and try use some salvaged parts. This is a....
