Top Circuits Page 138
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This is an example how to interface to the standard Hitachi-44780 LCD using an 8051 microcontroller and SDCC as C Compiler. I use a standard 16-character by 2-line LCD module, see schematic below. Here, I use 4-bit interfacing...
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As mentioned in the chapter about the DAC, this circuit shifts the voltage output range. The following diagram explains it's operation and structure. The circuits outputs are connected to the input pins of the power opamps...
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A bike with 35 watt HS1 bulb and I want to upgrade brightness of headlight so I decided to put H4 60/65 watt xenon bulb. An expert on this forum suggested me to use relays as the new bulb requires more power. I did some google to understand relays and how to....
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A microprocessor cannot drive a motor directly, since it cannot supply enough current. Instead, there must be some interface circuitry so that the motor power is supplied from another power source and only the control signals derive from the microprocessor.....
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As more than one switches are to be controlled, we have to transmit a number of bits through IR transmission to indicate which is key is pressed on the remote and accordingly which switch of the switch-board to control. In this project, this is done by using....
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Microcontrollers are integrated circuits which consists of microprocessor with additional units like memories, input/output units (peripherals), etc. With this way of implementation, microcontrollers provide savings in time and space, and of course money.....
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The modification I`ve made is based on Steve Chambers SC1 modification and the further improvement by Phil Davis, but does not use the additional parallel port connection. I consider all differences from the original SC1 modification and Phil`s improvement....
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The power supply is just a 7812 voltage regulator followed by an op-amp set to 6V to create a half way supply voltage for the audio op-amp stages. A 12V regulator seems to be too high for a battery fed application. These 4 outputs are all followed by a....
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The unit is designed around an ordinary op-amp and easy to obtain parts. Reverse engineered circuit diagram of Anatek 50-1S variable power supply shown below. Circuit board layout does not seem all that critical and as you can see from the schematic that....
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This is the type that has a little DC motor fan positioned above a small container containing a deoderant liquid or jelly, and runs off a D cell. The photocell turns off the fan when it gets dark. The LED flashes if the battery is good...
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This is an unusual design in that it uses plain metal gate CMOS logic instead of the usual PIC or a custom chip. The 22uF capacitor charges up during one half of the ac cycle, and supplies trigger current to the triac on both halves...
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A similar circuit can be used with an 8 ohm speaker but in that case you would put it in place of the emitter resistor. This circuit works as a carbon microphone replacement...
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A nice design which even turns off if the pushbutton is held depressed or jammed a long time. Not re-triggerable while the light is still on though(Thanks for pointing that out Watson): Below is one that starts off bright and slowly dims out to nothing. They....
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This must generate an awfull lot of RFI without a choke! The house wiring supplies the di/dt limiting. This is a CHEAP design which exhibits hysterisys at dim settings. Not everything made and sold to the public is top notch...
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This one is particularly loud even though it runs on only two AA batteries. It uses a push-pull transformer output. This unit was manufactured with the 10K resistor at pin 4 instead of pin 3 due to a PCB layout error:..
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Did not bother to draw out the receiver section because it is quite ordinary. The TRIAC switch section shown below can be controlled by ordinary 4000 series CMOS logic...
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The receiver has a bigger motor to drive the wheels and a smaller motor to drive the steering which is not proportional. You could add an extra channel to the receiver by using the spare latch. Again there is no separate on/off switch on the transmitter....
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By using diodes in place of pull up resistors, and by isolating the DC load from the trigger circuit via junction drops and the 10nF capacitor. If there is too much power comming from the solar cell then the motor might run too often or even continuously.....
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This is an actual reverse engineered circuit diagram of the one transistor circuit most commonly used to drive Permanent Magnet DC motors in childrens` toys. This type of circuit almost always uses the 625mW version of the ubiquitous 8050 or 8550 transistor.....
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A higher end version of the same thing, with a few extra user selectable settings to allow audible as well as ultrasonic output so it can be more effective against animals:..
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The total dollars count for all parts is much smaller that the cost of an heavy duty DPDT foot switch. As seen on the previous page suggested electronic switch circuits can be made easily and I have found that their applications is justified. New mechanical....
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This project was developed as an inexpensive way to drive small dc brushed motors as positioning servos for use on a desktop sized CNC machine. The board is interfaced to the PC through 2 pins of a parallel port. The drive signal on these pins is known as....
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Decided to quench my curiosity and see if a PICAXE-18X chip running at 4Mhz. was capable of this application. I also wanted to have a go at a project from the ground up. Designing the circuit, drawing up the printed circuit board artwork, etching the circuit....
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Diode, D13, provides different timings for the forward sweep, and the retrace which can be faster than the forward sweep. Outputs are generated to tell the blanking circuit when to blank the CRT and when to unblank the CRT. The sync trigger input provides....
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An embedded system which is used for tracking and positioning of any vehicle by using Global Positioning System (GPS) and Global system for mobile communication (GSM). In this project AT89S52 microcontroller is used for interfacing to various hardware....
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This digital volume control has no pot to wear out and introduces almost no noise in the circuit. Instead, the volume is controlled by pressing UP and DOWN. A digital potentiometer is a digitally-controlled electronic component that mimics the analog....
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This hardware is used to display the number of cars in the parking lot. Basically, this board has six-segment display but using only one display can do our work. It used segment driver IC SN7447AN and 3*8 decoder to select the corresponding display. This....
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At89s51 microcontroller will be the main component controlling the process, and display different digits on display. The seven segment display is found in many electronic devices. It is just 7 LEDs that have been combined into one case to make a convenient....
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It is 8-Bit, Microprocessor-Compatible, A/D Converters. Data Collection Analog to Digital Conversion and Communicating and It uses an ADC0804 chip to convert from analog to digital, an AT89C2051. The ADC0802 families are CMOS 8-Bit, successive-approximation....
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the moving message will be display on the LCD which will be controlled through microcontroller and the message will be sent by computer using RS232. The circuit diagram of the moving message display is shown in this post and how the whole process is....
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This project is developed to control up to 50 solid state relays individually. The project is good learning material for students who which to expand the input output lines of microcontroller and want to control many devices. 2. The ON or OFF status of each....
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This project is output port expander of microcontroller 8051. In this project we will learn, how to interface a large load bank with microcontroller 8051. In this load bank project, up to 50 solid state relays are interfaced with microcontroller using shift....
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This project is currently output two PWM signals but can be extended to many PWM signals very easy. The input to the microcontroller is 100HZ pulses as zero crossing. currently it is build for two channel DAC, the input at port1 and port2 of microcontroller....
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This is example project in which the 8051 is Producing PWM outputs for seperate two channels, The PWM can be used to control the phase angle of SCR or triace for power control of any AC load like Heater Motor Fan, this project can be used as heater power....
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The hardware configuration when using multiple 1-Wire temperature sensors like the DS1820 is very simple, as illustrated in the block diagram below. A single-wire bus is used for communication between the microcontroller and the temperature sensor. It is....
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The hardware configuration when using multiple 1-Wire temperature sensors like the DS1820 is very simple, as illustrated in the block diagram below. A single-wire bus is used for communication between the microcontroller and the temperature sensor. It is....
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The objective of this project is to make a controller based model to count number of persons visiting particular room and accordingly light up the room. Here we can use sensor and can know present number of persons. In today`s world, there is a continuous....
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This simple circuit has helped me out on many occasions. It is able to check transistors, in the circuit, down to 40 ohms across the collector-base or base-emitter junctions. It can also check the output power transistors on amplifier circuits. Circuit....
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The detector is intended to sense and signal to another circuit that an appliance is connected to the mains voltage. For this purpose, an optocoupler, IC1 in the circuit, is used. The light-emitting diode in this device is connected across the mains voltage....
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Half of RL1 and RL2 manipulate the switching and the other is connected to an application. Relays are 200 ohms above ground and at one point are referenced to positive that turns them off. RL1 (which is off) applies plus voltage from its armature and latches....
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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 1. 8KHz. The filter is....
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This is a project I`ve done on behalf of a person on an internet forum. The requested operation is simple: Use an EasyDriver stepper motor driver and a 1. 8 deg/rotation stepper motor and make the motor turn one revolution per minute. This frees me up a bit....
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This circuit is used on the ATMEL Microcontroller IC. However, the circuit is used for Microcontroller AT89Sxx. and ATMEGA xxx if you know about MISO, MOSI, SCK AND RESET..
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This transmitter has a size about that of a large coat button. The transmitter accepts direct voice input and work on a single watch type button cell that serves several tens of hours together. As shown in schematic the transmitter is probably the simplest....
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This was my first published article, and fell out of my work on the homebrew 8008 system that is now in the Computer History Museum (that link includes four detailed photos). It`s basically a one-way simple UAR/T, though those devices were pricey back then....
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This second issue of the Bikelab Notes, published during my time building BEHEMOTH at Sun Microsystems, focuses on the high-brightness LED taillight assemblies. These were not commercially available at the time, so this was a hack. I also commented on the....
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This is the complete design for a microprocessor-controlled, environmentally sealed 8" video turret with two cameras, remote or autofocus, zoom control, sun damage protection, 450-degree azimuth rotation, 9-speed scan and point capability, multidrop network....
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This is the seventh part of an ongoing series about building a low cost, open source streaming internet radio. If you haven`t already, check out the previous parts (see the links at the end of this article) for some background about the project. In part six,....
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Modifying the MXR Micro Amp for True Bypass switching, requiring tricky circuit board surgery due to its original surface-mount DPDT switch....
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A SIM Card also known as Subscriber Identity Module, A SIM is a Smart Card that can store data from a cellular phone. Those data like identity, location and phone number, network authorization data, personal security keys, contact lists and stored text....
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The goal of this project was to build a circuit that would monitor a person`s sleep activity and, eventually, give feedback on that activity to the user. The purpose of this was to induce lucid dreaming in the subject. When sleeping, people generally....
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By now many audio DIYers would be familiar with "What Compressor ", a project that apparently had its origins in one man`s dissatisfaction with Alesis` 3630 compressor and his fascination with a friend`s Joe Meek device. DeeT, as he calls himself, generously....
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After having its engine and other mechanical parts restored to its optimum condition, the next thing I had in mind is to add aesthetic lighting. I went to a local electronics store and found these 12V DC Operated LED Strip. These are perfect for what I had....
-
-
Arduino is an open-source electronics prototyping platform based on flexible, easy-to-use hardware and software. It`s intended for artists, designers, hobbyists, and anyone interested in creating interactive objects or environments. Arduino can sense the....
-
In this section,one of the most useful Integrated Circuits or IC, more commonly known as the 555 Timer chip will be discussed. It should be noted that IC`s....
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DC Voltage Regulator (NPN & Zener Regulator) There are instances where it is handy to have a regulated DC voltage power supply for use on your model....
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An amplifier is something that amplified the voltage on a circuit. The most basic kind is an operational amplifier, and this video will show you how these work and how to use them in your electronics. As an example you`ll learn how to make a microphone....
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Learn how to build h-bridges from many on- and off-line resources. After all these circuits are not terribly complicated. Some of those resources are good, some are not so much. However when I`ve started working with them, I`ve realized that many of my....
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Which type of modulated light receiver should one use A photodiode straight into a high gain, high impedance amplifier A photodiode into a current amplifier A back-biased photodiode FET input or bipolar IC or discrete How does one minimise noise while....
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After constructing the Pulse Width Modulator for High Power LEDs I needed to build another LED modulator for another optical transceiver. For this project I decided to take a different approach and use solely linear techniques for the audio modulation. Like....
-
Fairly early on in my work with high-power LEDs such the Luxeon 1 and 3 watt devices I considered that PWM (Pulse Width Modulation) techniques would be an interesting means of modulation the LED. In theory, this should be capable of producing the lowest....
-
The use of optical filters to reduce/remove light from other sources. If a fairly narrowband optical filter were used on the receiver, "off-wavelength" light could be rejected - but such filters are quite expensive, they can be difficult to implement on a....
-
All optical transmitters will contain circuitry to limit the current to a value that will be safe enough to protect the LED during short-term accidents. Red, Red-Orange, and Amber Luxeon I LEDs have a much lower peak current rating - about 550 mA. At this....
-
As it turns out, many types of LEDs appear to exhibit gain effects akin to those of an avalanche photo diode when reverse-biased - an effect that has been observed in the 25-300 volt area with the voltage, spectral response, and overall sensitivity/gain....
-
-
This is of course the simplest electronic code lock circuit one can make. The circuit uses one transistor, a relay and few passive components. The simplicity does not have any influence on the performance and this circuit works really fine. The circuit is....
This is an example how to interface to the standard Hitachi-44780 LCD using an 8051 microcontroller and SDCC as C Compiler. I use a standard 16-character by 2-line LCD module, see schematic below. Here, I use 4-bit interfacing...
As mentioned in the chapter about the DAC, this circuit shifts the voltage output range. The following diagram explains it's operation and structure. The circuits outputs are connected to the input pins of the power opamps...
A bike with 35 watt HS1 bulb and I want to upgrade brightness of headlight so I decided to put H4 60/65 watt xenon bulb. An expert on this forum suggested me to use relays as the new bulb requires more power. I did some google to understand relays and how to....
A microprocessor cannot drive a motor directly, since it cannot supply enough current. Instead, there must be some interface circuitry so that the motor power is supplied from another power source and only the control signals derive from the microprocessor.....
As more than one switches are to be controlled, we have to transmit a number of bits through IR transmission to indicate which is key is pressed on the remote and accordingly which switch of the switch-board to control. In this project, this is done by using....
Microcontrollers are integrated circuits which consists of microprocessor with additional units like memories, input/output units (peripherals), etc. With this way of implementation, microcontrollers provide savings in time and space, and of course money.....
The modification I`ve made is based on Steve Chambers SC1 modification and the further improvement by Phil Davis, but does not use the additional parallel port connection. I consider all differences from the original SC1 modification and Phil`s improvement....
The power supply is just a 7812 voltage regulator followed by an op-amp set to 6V to create a half way supply voltage for the audio op-amp stages. A 12V regulator seems to be too high for a battery fed application. These 4 outputs are all followed by a....
The unit is designed around an ordinary op-amp and easy to obtain parts. Reverse engineered circuit diagram of Anatek 50-1S variable power supply shown below. Circuit board layout does not seem all that critical and as you can see from the schematic that....
A nice design which even turns off if the pushbutton is held depressed or jammed a long time. Not re-triggerable while the light is still on though(Thanks for pointing that out Watson): Below is one that starts off bright and slowly dims out to nothing. They....
This one is particularly loud even though it runs on only two AA batteries. It uses a push-pull transformer output. This unit was manufactured with the 10K resistor at pin 4 instead of pin 3 due to a PCB layout error:..
The receiver has a bigger motor to drive the wheels and a smaller motor to drive the steering which is not proportional. You could add an extra channel to the receiver by using the spare latch. Again there is no separate on/off switch on the transmitter....
A higher end version of the same thing, with a few extra user selectable settings to allow audible as well as ultrasonic output so it can be more effective against animals:..
The total dollars count for all parts is much smaller that the cost of an heavy duty DPDT foot switch. As seen on the previous page suggested electronic switch circuits can be made easily and I have found that their applications is justified. New mechanical....
This project was developed as an inexpensive way to drive small dc brushed motors as positioning servos for use on a desktop sized CNC machine. The board is interfaced to the PC through 2 pins of a parallel port. The drive signal on these pins is known as....
Decided to quench my curiosity and see if a PICAXE-18X chip running at 4Mhz. was capable of this application. I also wanted to have a go at a project from the ground up. Designing the circuit, drawing up the printed circuit board artwork, etching the circuit....
Diode, D13, provides different timings for the forward sweep, and the retrace which can be faster than the forward sweep. Outputs are generated to tell the blanking circuit when to blank the CRT and when to unblank the CRT. The sync trigger input provides....
An embedded system which is used for tracking and positioning of any vehicle by using Global Positioning System (GPS) and Global system for mobile communication (GSM). In this project AT89S52 microcontroller is used for interfacing to various hardware....
This digital volume control has no pot to wear out and introduces almost no noise in the circuit. Instead, the volume is controlled by pressing UP and DOWN. A digital potentiometer is a digitally-controlled electronic component that mimics the analog....
This hardware is used to display the number of cars in the parking lot. Basically, this board has six-segment display but using only one display can do our work. It used segment driver IC SN7447AN and 3*8 decoder to select the corresponding display. This....
At89s51 microcontroller will be the main component controlling the process, and display different digits on display. The seven segment display is found in many electronic devices. It is just 7 LEDs that have been combined into one case to make a convenient....
It is 8-Bit, Microprocessor-Compatible, A/D Converters. Data Collection Analog to Digital Conversion and Communicating and It uses an ADC0804 chip to convert from analog to digital, an AT89C2051. The ADC0802 families are CMOS 8-Bit, successive-approximation....
the moving message will be display on the LCD which will be controlled through microcontroller and the message will be sent by computer using RS232. The circuit diagram of the moving message display is shown in this post and how the whole process is....
This project is developed to control up to 50 solid state relays individually. The project is good learning material for students who which to expand the input output lines of microcontroller and want to control many devices. 2. The ON or OFF status of each....
This project is output port expander of microcontroller 8051. In this project we will learn, how to interface a large load bank with microcontroller 8051. In this load bank project, up to 50 solid state relays are interfaced with microcontroller using shift....
This project is currently output two PWM signals but can be extended to many PWM signals very easy. The input to the microcontroller is 100HZ pulses as zero crossing. currently it is build for two channel DAC, the input at port1 and port2 of microcontroller....
This is example project in which the 8051 is Producing PWM outputs for seperate two channels, The PWM can be used to control the phase angle of SCR or triace for power control of any AC load like Heater Motor Fan, this project can be used as heater power....
The hardware configuration when using multiple 1-Wire temperature sensors like the DS1820 is very simple, as illustrated in the block diagram below. A single-wire bus is used for communication between the microcontroller and the temperature sensor. It is....
The hardware configuration when using multiple 1-Wire temperature sensors like the DS1820 is very simple, as illustrated in the block diagram below. A single-wire bus is used for communication between the microcontroller and the temperature sensor. It is....
The objective of this project is to make a controller based model to count number of persons visiting particular room and accordingly light up the room. Here we can use sensor and can know present number of persons. In today`s world, there is a continuous....
This simple circuit has helped me out on many occasions. It is able to check transistors, in the circuit, down to 40 ohms across the collector-base or base-emitter junctions. It can also check the output power transistors on amplifier circuits. Circuit....
The detector is intended to sense and signal to another circuit that an appliance is connected to the mains voltage. For this purpose, an optocoupler, IC1 in the circuit, is used. The light-emitting diode in this device is connected across the mains voltage....
Half of RL1 and RL2 manipulate the switching and the other is connected to an application. Relays are 200 ohms above ground and at one point are referenced to positive that turns them off. RL1 (which is off) applies plus voltage from its armature and latches....
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 1. 8KHz. The filter is....
This is a project I`ve done on behalf of a person on an internet forum. The requested operation is simple: Use an EasyDriver stepper motor driver and a 1. 8 deg/rotation stepper motor and make the motor turn one revolution per minute. This frees me up a bit....
This circuit is used on the ATMEL Microcontroller IC. However, the circuit is used for Microcontroller AT89Sxx. and ATMEGA xxx if you know about MISO, MOSI, SCK AND RESET..
This transmitter has a size about that of a large coat button. The transmitter accepts direct voice input and work on a single watch type button cell that serves several tens of hours together. As shown in schematic the transmitter is probably the simplest....
This was my first published article, and fell out of my work on the homebrew 8008 system that is now in the Computer History Museum (that link includes four detailed photos). It`s basically a one-way simple UAR/T, though those devices were pricey back then....
This second issue of the Bikelab Notes, published during my time building BEHEMOTH at Sun Microsystems, focuses on the high-brightness LED taillight assemblies. These were not commercially available at the time, so this was a hack. I also commented on the....
This is the complete design for a microprocessor-controlled, environmentally sealed 8" video turret with two cameras, remote or autofocus, zoom control, sun damage protection, 450-degree azimuth rotation, 9-speed scan and point capability, multidrop network....
This is the seventh part of an ongoing series about building a low cost, open source streaming internet radio. If you haven`t already, check out the previous parts (see the links at the end of this article) for some background about the project. In part six,....
Modifying the MXR Micro Amp for True Bypass switching, requiring tricky circuit board surgery due to its original surface-mount DPDT switch....
A SIM Card also known as Subscriber Identity Module, A SIM is a Smart Card that can store data from a cellular phone. Those data like identity, location and phone number, network authorization data, personal security keys, contact lists and stored text....
By now many audio DIYers would be familiar with "What Compressor ", a project that apparently had its origins in one man`s dissatisfaction with Alesis` 3630 compressor and his fascination with a friend`s Joe Meek device. DeeT, as he calls himself, generously....
After having its engine and other mechanical parts restored to its optimum condition, the next thing I had in mind is to add aesthetic lighting. I went to a local electronics store and found these 12V DC Operated LED Strip. These are perfect for what I had....
Arduino is an open-source electronics prototyping platform based on flexible, easy-to-use hardware and software. It`s intended for artists, designers, hobbyists, and anyone interested in creating interactive objects or environments. Arduino can sense the....
In this section,one of the most useful Integrated Circuits or IC, more commonly known as the 555 Timer chip will be discussed. It should be noted that IC`s....
DC Voltage Regulator (NPN & Zener Regulator) There are instances where it is handy to have a regulated DC voltage power supply for use on your model....
An amplifier is something that amplified the voltage on a circuit. The most basic kind is an operational amplifier, and this video will show you how these work and how to use them in your electronics. As an example you`ll learn how to make a microphone....
Learn how to build h-bridges from many on- and off-line resources. After all these circuits are not terribly complicated. Some of those resources are good, some are not so much. However when I`ve started working with them, I`ve realized that many of my....
Which type of modulated light receiver should one use A photodiode straight into a high gain, high impedance amplifier A photodiode into a current amplifier A back-biased photodiode FET input or bipolar IC or discrete How does one minimise noise while....
After constructing the Pulse Width Modulator for High Power LEDs I needed to build another LED modulator for another optical transceiver. For this project I decided to take a different approach and use solely linear techniques for the audio modulation. Like....
Fairly early on in my work with high-power LEDs such the Luxeon 1 and 3 watt devices I considered that PWM (Pulse Width Modulation) techniques would be an interesting means of modulation the LED. In theory, this should be capable of producing the lowest....
The use of optical filters to reduce/remove light from other sources. If a fairly narrowband optical filter were used on the receiver, "off-wavelength" light could be rejected - but such filters are quite expensive, they can be difficult to implement on a....
All optical transmitters will contain circuitry to limit the current to a value that will be safe enough to protect the LED during short-term accidents. Red, Red-Orange, and Amber Luxeon I LEDs have a much lower peak current rating - about 550 mA. At this....
As it turns out, many types of LEDs appear to exhibit gain effects akin to those of an avalanche photo diode when reverse-biased - an effect that has been observed in the 25-300 volt area with the voltage, spectral response, and overall sensitivity/gain....
This is of course the simplest electronic code lock circuit one can make. The circuit uses one transistor, a relay and few passive components. The simplicity does not have any influence on the performance and this circuit works really fine. The circuit is....
