Top Circuits Page 162
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This basic PIC-based RS-232 serial interface can control up to 120 digital TTL outputs....
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This smart doorbell system is designed for use in industrial environments. It is microcontroller based and controls a horn and a flash light....
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This page describes a battery tester I designed. It will characterize your batteries and save the results on an microSD card....
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The K8000 DAC High Power Amplifier is an electronic amplifier whose output can be regulated between 0 and 9 V with an output current of up to 9 Amp?res....
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This I2C expansion board for microcontrollers allows you to connect 8 switches or 8 LEDs with only two wires....
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I have created a light computer that generates an effect like the scanner of the car KITT in the TV series Knight Rider. You can see a visualization of the effect in the image below: Many circuits on the Internet are built with a CD4017 counter IC. I myself....
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This project describes a light effect that is similar to the one of the car in the TV series `Knight Rider`....
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This PIC-based hardware circuit accepts texts from a PS/2 keyboard and converts it into a morse code audio signal....
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This page is about an old LM032L LCD module from Hitachi. I found an old one and tried to make it work. The module can display 2 lines with 20 characters each. This page will describe how I got the module to work on a PIC 16F84A microcontroller. First I had....
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The PC Standby Detector is a small circuit to disable the power LED when the PC is in standby mode....
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The cell we will use for our solar tracking experiment is made from crystalline silicon and has a maximum voltage rating of. 55V and a maximum current rating of 300 ma. The cell can be picked up in your local Radio Shack for about $5. Although the cell....
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Voice Electric (FC52) is converted to electrical signals. FC52 at cost benefits of high glucose amplifier, can amplify the audio signal. When the clapping sound when, Y the sound signal is converted to electrical signals, and add to the inverting input of....
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LM117/LM317 National Semiconductor Corporation is a three-terminal adjustable positive voltage regulator ICs. LM117/LM317 output voltage range is 1. 2V to 37V, load current up to 1. 5A. It`s very simple to use, only two external resistors to set the output....
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Network with Cadence technologists and peers in the Cadence Community. Stay abreast of technology trends, news and opinion through Blogs, forums, and social networking....
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The provided connections will provide configuration free usage for most Arduino boards. Some Arduino boards, such as the Mega2560, will require custom configuration. This is determined by how the ports on the Atmel AVR microcontroller are mapped to the....
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The PZP-1 Piezo Buffer is now available! The PZP-1 is a high impedance buffer preamp, using 100% discrete class-A circuitry. Designed expressly for the Fender Precision acoustic/electric and HMT basses, it can also help other instruments with piezoelectric....
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How to make the tally light work on the F15 camera viewfinder when you don`t have the CCU/RCU....
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The PIC18F4550 chip contains more features than the PIC16F including a module for USB communications. There is some added complexity. The first issue to resolve is which chip to order. The PICSTART Plus will program the 40 pin PIC18F4550-I/P chip. The....
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I learned that you could do PWM with the 555 chip. So I tested this idea. I will not attempt to explain the workings of the 555 chip because I found the page by Tony van Roon to be an excellent introduction to the 555 chip. Tony`s page discusses a slightly....
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My neighbor`s drill charger stopped working. I found that the primary wires in the transformer were non-functional. This charger had a very simple design. It used a transformer, followed by a diode bridge and a larger resistor. The power supply indicated it....
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You will need a few items to begin working with microcontrollers. I purchased the PICSTART Plus Part Number: DV003001 kit from Microchip. This kit includes the following: A sample PIC16F84 microcontroller chip: My kit actually came with a PIC16F84A chip.....
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This project started because I wanted a Li-ion charging circuit with more flexibility than afforded by other do-it-yourself circuits, but at less cost than the programmable computerized chargers. The goal from the beginning was to design, build, test and....
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Design cicuit using a power mosfet to replace the NTC (thermister) that many Mag623 users employ to prevent their bulbs from flashing. Although inexpensive and easy to hook up, NTC`s run quite hot. They are also affected by ambient temperature, require a....
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I`m looking for a circuit (the simpler and cheaper, the better) that can drive three or more LEDs at 200-350mA each, randomly flashing/strobing them at 5-20Hz. Input power should be low-voltage DC. A range for Vin, instead of an exact 5.0V or whatever, would....
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Didn`t measure my resisitors exactly and since they are +/-5% and Vref has a range of 1. 2 to 1. 3 volts you can easily end up over 6 volts. Here is a worst case example: The reason that I disagree with that statement is that they clearly work well in....
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In this schematic, provided by Jimmy M, would this circuit drain the batteries when the light is not in use? I`m considering building a mosfet circuit like this to use in a compact M@g where I discard the original bulky switch and use a microswitch to....
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My father-in-law wants to do something unique for his outdoor Christmas decorations and I told him Id help. He wants an LED-illuminated star to hang on his house that will be very-bright. (Of course my definition of very-bright is quite different than his)....
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Anyone know how I could make an led come on when it gets dark automatically?I made a version with a relay and photoresistor that worked but then I was think won`t that drain the battery to much?I`m trying to use this in conjunction with a circuit I got from....
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edit - There are information not included in this main post. Read through the thread for more information on timer calibration and other useful information by cpfers. - PEU pointed out the TX to be connected to serial port pin 2 instead of 3. This now....
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Did you take that shorting wire off the resistor What about your pot, did you leave it cranked on full power What kind of increase do you think turning the pot gave you Good I suppose. I haven`t yet disconnected the shorting wire, but at the same time I....
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A low-voltage demonstration Tesla coil using a solid-state photovoltaic relay to replace the conventional spark gap has been analyzed and then built. This relay incorporates an isolated LED to illuminate a silicon photovoltaic stack which drives a....
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Propclocks are really pretty complex devices, utilizing a PIC microcomputer that performs instructions at 10mhz. The PIC is the brain of the device and does most of the work involved in making the LEDs light up at just the right time so that it appears there....
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And normally tuning is not easy: you`ll fire the system up and try to notice the spark length, shut it off (and pull the plug!), re-tune (move the tap on the primary), fire it up again and try to remember the spark length of the run before, and do it all....
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Need a little help getting this schematic figured out, most of it is understood with the exception of the triangular objects(amps-opamps?) Not sure what those are or how to implement and order them. Here is the diagram thus far(planning to test with a lpf at....
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This design adapts such a high voltage flash for use on a low voltage camera by using an optocoupler to electronically isolate the camera`s contacts from the high voltage. It can then be triggered by the camera using the 6 volt supply from the flash unit`s....
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The device will be placed on the back wheel of the bicycle. Since the LED`s and other components run off of a lithium-ion battery, it stands independently, attached to the spokes of the rear wheel. In the design, all components are placed on the spokes of....
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Step-by-Step instructions for adding a remote control interface to F/G CED players which can be used with a variety of Atari and Sega joysticks including wireless infrared controllers....
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Descriptions of the various modules in a home built music synthesizer - Sub-oscillator project. ....
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This was originally developed a timing accessory for a sequencer I was working on, though when fed from a VCO, interesting frequency trills like those of the old 8-bit computer games can be produced. Feeding the control voltage from a Psycho LFO produces....
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The schematic of the updated power filtering on the R2 PCBs. One of each of the 100n capacitors could be replaced with 10n, or even 220pF to improve the spread of response times to spikes. The Super Psycho Modulation Source is a fairly simple circuit with a....
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This module is an enhanced version of the D. C. mixer designed for both audio and CV mixing. It has both non-inverting (adding) and inverting (subtracting) inputs, as well as a master level control. It also features two inverting outputs, one (out2) that is....
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This module is a "tribute" module, based on the awesome Steiner-Parker Synth VCF. Those who know me will know I`m not a big VCF fan. Nonetheless, this VCF really appeals to me. Its sound is quite unlike the Moog ladder, has a lot of character. Resonance is a....
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The CGS89 is a sequencer designed for delivering pulsed or gated events, for rhythm and percussion, triggering other sequencers, or selecting stages in Programmers such as the Serge R15 PRG. It can be used as a replacement for the first generation Serge R10....
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Electronic project describing a D.C. Mixer for Synthesizers and other control applications....
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The VCO presented here is a direct derivative of the original oscillator invented by Friedrich Trautwein in 1932. And it perfectly demonstrates why I`m so cynical about the music world: the Mixtur-Trautonium oscillator was a true VCO, invented at a time when....
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A microprocessor controlled shutter control-box for electrically driven shutters such as the MELLES GRIOT 04 IES 003 and others, such as the ILEX electric shutters. Older view camera lenses often come in shutters that have problems from use or age. Usually a....
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On several occasions, Acorn`s initial specifications for a new machine and the final product have differed considerably in the features they provide. For example, the Risc PC`s motherboard SCSI controller and Phoebe`s ultra-fast scratch memory were consigned....
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The idea was to show time passing, but instead of a traditional clock face or digits or lights representing binary, to use some kind of tactile feedback. A simple vibrate motor was an obvious choice - used as `force feedback` actuators in video-game console....
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The crock pot is attached to a relay that can switch it on or off. The relay is toggled by a microcontroller based on readings from a temperature sensor ( thermistor ) placed inside the crock pot. Heat the milk to 185 °F (85 °C). This kills off microbes to....
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This device was created in a hurry for the USC Rocket Propulsion Lab, the student-run high-altitude rocketry effort at USC. I think I soldered it together a day or two before the launch, and then programmed it on a laptop on the car trip out to the desert.....
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There is now no need for a separate camera and recorder - for less money you can buy an integrated dash camera that will record in HD. Try the Techmoan blog for some reviews. Summary - this is a description of how to install a fairly cheap video recording....
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When I started out making pickups, I had just bought a bigger lathe and had one of those mini one that I was just going to sell. I instead turned it into a wi....
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The input transistor Q2 is an N-channel JFET. Each particular JFET sets a particular output bias voltage, so the JFET must be selected from among multiple devices for the desired bias value. Fortunately, due to the low current involved, desirable devices can....
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This two-zone alarm has automatic exit, entry and siren cut-off timers. It was developed for the Beginner`s Guide To Cmos Timers. So it has a particularly detailed circuit description. There`s an optional One-Time-Only module. It will force the siren to....
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When this alarm is activated its Siren will sound once - for up to 20-minutes. Then it will switch off and remain off. The basic circuit has a single zone with independently adjustable Exit and Entry delays. This will be adequate in many situations. However,....
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This is a simple SCR based burglar alarm circuit. Its features include automatic Exit and Entry delays - together with a timed Bell Cut-off and Reset. The basic alarm has a single zone. This will be adequate in many situations. However - the modular design....
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This transistor based alarm features automatic Exit and Entry delays - together with a timed Bell Cut-off and system Reset. Along with the Exit/Entry zone - the basic alarm board has one Instant Zone. This will be adequate in many situations. However - the....
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The circuit features automatic Exit and Entry delays, timed Bell Cut-off and System Reset. It has provision for normally-open and normally-closed switches and will suit the usual input devices (Pressure Mats, Magnetic Reed contacts, Foil Tape, PIRs and....
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This circuit features automatic Exit/Entry delays, timed Bell Cut-off and System Reset. It has provision for normally-open and normally-closed switches and will accommodate the usual input devices (Pressure Mats, Magnetic Reed contacts, Foil Tape, PIRs and....
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This circuit features automatic Exit/Entry delays, timed Bell Cut-off and System Reset. It will accommodate the usual normally-closed input devices (Magnetic Reed contacts, Micro Switches, Foil Tape and PIRs). And - with a simple modification - a....
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This is a single zone alarm - with automatic exit, entry and siren cut-off timers. It will accommodate all the usual types of normally-closed input devices - such as magnetic reed contacts, foil tape, PIRs etc. But it`s easy to add a normally-open trigger.....
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This is a selection of small self-contained alarm circuits. They have a very low standby current; and are suitable for battery operation. Some are triggered by normally-open and normally-closed switches. Some react to changes in light or temperature. The....
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This is a basic single-zone burglar alarm circuit. Its features include automatic Exit and Entry delays - and an optional Siren Cut-Off timer. It has an extremely small standby current. This makes it ideal for battery-powered operation. Use it in your....
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This is an enhanced version of the simple Garage/Shed Alarm. The Entry and Exit delays have been increased to about 30-seconds - and I`ve added a timed Siren cut-off and automatic Reset. I`ve also replaced the LED with an entry Buzzer. These enhancements....
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This Keypad is suitable for the Modular Burglar Alarm. However, it has other applications. Pressing a single key will energize the relay. Entering the Four-Digit code of your choice will de-energize it....
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This Keypad is suitable for the Modular Burglar Alarm. However, it has other applications. Entering the First Four Digits of your chosen Five-Digit code - will energize the relay. Entering the Full Five-Digit code - will de-energize it....
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This circuit, enclosed in a small plastic box, can be placed into a bag or handbag. A small magnet is placed close to the reed switch and connected to the hand or the clothes of the person carrying the bag by means of a tiny cord. If the bag is snatched....
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A complementary transistor pair (Q2 & Q3) is wired as a high efficiency oscillator, directly driving the loudspeaker. Q1 ensures a full charge of C2 when power is applied to the circuit. Pressing on P1, C2 gradually discharges through R8: the circuit starts....
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This car alarm circuit features Exit and Entry delays, an instant alarm zone, an intermittent siren output and automatic Reset. By adding external relays you can immobilize the vehicle and flash the lights....
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This is a Universal version of the Four-Digit Alarm Control Keypad. I have modified the design to free up the relay contacts. This allows the circuit to operate as a general-purpose switch. I`ve used a SPCO/SPDT relay - but you can use a multi-pole relay if....
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This is a simplified version of the 4-Digit Keypad Controlled Switch. I have modified the design to reduce the complexity of the circuit - and the number of components required. As a result - the code is somewhat less secure. However, there should be lots of....
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This circuit is designed to operate an electrical door-release mechanism - but it will have other applications. When you enter the four-digit code of your choice - the relay will energize for a preset time period. Use the relay contacts to power the release....
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The digital lock shown below uses 4 common logic ICs to allow controlling a relay by entering a 4 digit number on a keypad. The first 4 outputs from the CD4017 decade counter (pins 3,2,4,7) are gated together with 4 digits from a keypad so that as the keys....
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The aim of this design is to reproduce a Combo amplifier of the type very common in the `sixties and the `seventies of the past century. It is well suited as a guitar amplifier but it will do a good job with any kind of electronic musical instrument or....
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This circuit [Fig.1] is a class AB stereo audio power amplifier designed by Quasar for quality hi-fi applications using a TDA2005 module. It is easy to construct and has a minimum of external components. The module has output current protection and thermal....
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This circuit was designed and manufactured the `80`s. From then it works without problem. It does not present any particular constructional problem, beyond known: the attention in the provided force of power supply - choice suitable heatsink and good....
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One still designing that it uses in the exit transistor of technology V-mosfet. This transistors to us offer a lot of virtues concerning the simple bipolar transistors, as high speeds, thermic stability, low distortion etc....
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Even if simple the circuit, plirej` all condition, regarding the distortion and the response of frequency. The resistance of entry is 250K and the load that can drive is between 100R and 2K....
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It is a very useful thing , to have a small headphone amplifier , capable of driving a couple of pairs phones. Fortunately, the headphone amp has a much easier job to do, in that neither the output power requirements nor the load characteristics are so....
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It`s a classic designing of final amplifier 35 W, with two EL34 in push-pull, from the Siemens and Halske, with year of designing 24/3/1953 and code SV410/1. The amplifier it worked from 1954 until 1989, whenever it came also out except operation, with mean....
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2 x 18W Hi-Fi Stereo Power Amplifier based around two TDA2030 ICs. It has good input sensitivity, low distortion, good operating stability and full protection against overloads and output short-circuits. It can be used as a booster amplifier for existing....