Top Circuits Page 265
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This is a phantom-powered FET preamplifier built into a 1/4" guitar cable, similar to the one on the Tillman site. There are only a couple of parts to the amplifier, so the difficulty was being able to trim and solder component leads to fit within the space....
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-
I`ve had this old amp for about years, and friend of mine has volunteered to do the work to restore it. This is a Webster-Chicago 166-1 amplifier....
-
Alright, my 2204 won`t bias properly. I can`t get the tubes to idle at more than about 14 W (435 V * 33 mA cathode current). I popped a set of old Telefunkens in, but the wouldn`t go much over 10 W (440 V * 23 mA). They bias just fine in the middle of pot....
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To my new bestest pals: Anyone with experience on the old Uni`s? Model 1221. Looking to switch her to el34`s from 6l6`s. Not the savviest in the tuber....
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and the most likely problem with my wiring is ME. My apologies for the long post but I thought the more information and pictures I can provide the....
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well i did a quick search, and i didnt find much on this issue my question is: Can anyone provide a diagram on how cruise control is wired up (94-....
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-
This neat device replaces the input transistors and associated circuitry on one TO-220 style device. I had some driver boards made by my printed circuit house and decided that replacing the original driver board with the new PCB...
-
A densitometer is one of the most valuable tools a darkroom enthusiast can employ. Up until recently, however, densitometers were expensive and bulky. Furthermore, densitometers which would talk to your computer and calculate effective film speed, contrast....
-
This is an Astable Multivibrator Circuit to alternately flash two LEDs. The R and C Values determine the frequency and the 470 ohm collector load resistors set the current to about 20 miliamp, when the circuit is operated at 12Volts. Frequncy is about 1Cylce....
-
This small FM transmitter with a range of about 50 meters designed for connection to the USB port. With lots of mini-transmitters then you have a comprehensive, action-packed radio program. Due to the power supply via the USB port of a high frequency....
-
A speed closed loop control of DC motor using back emf sensing. Running a DC motor in one direction, just replace the LED with DC motor and remove the current limit resistor. Please note that motordirection reversal is not possible with this configuration.....
-
-
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....
-
A low cost high performance programmable home security system using few LDR`s as an input sensors. When above sensor(s) get triggered system may dial the user specified phone number (using build-in DTMF generator) and activate the high power audio alarm and....
-
A robot that operates when you give messages through your phone. Your mobile becomes your remote controller of your robot. Yes, it means if robot is in London, and you are in Mumbai, you can still control your robot. A super project for diploma students that....
-
This is a simple touch switch circuit, the 555 timer is configured as a one shot multivibrator that is triggered by touching the touch terminal. In this monostable mode, the timer generates a fixed pulse of about 4 seconds whenever the trigger voltage falls....
-
This is a simple alarm circuit which produces a musical tone when water or some conducting liquid comes in contact with the two sensor wires provided. The circuit is based on four transistors and one melody generator IC (M 3482). When water comes in contact....
-
This ultrasonic movement detector circuit uses a crystal locked circuit to get maximum performance from the ultrasonic transmitter. However, the detection circuit is different. think it is more sensitive. Check all the components against the parts list. It....
-
This wideband jammer simultaneously blocks all transmissions within a desired band typically by sweeping across the desired band to be blocked, starting at the lowest frequency and ending at the highest frequency of the band. For this purpose a linear....
-
A slot-loading Xbox 360 Slot loading, you know, like on a MacBook, where you put a CD or DVD in a thin auto-loading slot instead of pushing a button to make a mechanical tray slide out. The Xbox 360 has a tray-loader. The PlayStation 3, by comparison, uses a....
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This circuit divides a 10 MHz reference to 1, 10, 100 or 1000 pulses per second. The pulse width is also jumper selectable with lots of choices. A sync input will align the pulses with an external pulse, say from a GPS receiver. The outputs are hiding over....
-
Using a similar circuit to the LF block converter, I`ve made a Schumann Resonance Converter that moves the near-DC signals up to around 2 kHz for an ordinary soundcard. Here`s the maiden run plot: It seems to work! The fuzzy lines below 30 Hz are due to the....
-
The purpose of this report is to provide background and findings or our senior project. We will discuss four steps that we used to complete our final project. The four steps of our project were research and development, design, construction, and test &....
-
The Amazing All-Band Receiver is basically a diode detector followed by a high-gain audio amplifier. This is not a multi-band receiver; it picks up everything at once! The detector uses a biased Schottky diode for excellent sensitivity and bandwidth; the....
-
The picture to the left is a high quality radio transmitter for the A. M. broadcast band. The transmitter legally operates with "micro-power" and will not set any distance records but, unlike simpler designs, the frequency stays put and the fidelity is....
-
Home-made antennas can greatly improve the performance of AM and FM radios, short-wave receivers, and scanners. If you are a talk-radio fan then experiment with the AM band antennas and you will be able to hear shows from all over the country with surprising....
-
The first choice is usually an integrated circuit designed for the purpose. A typical assortment can be seen on this National Semiconductor page. Discrete designs can also be built with readily available transistors or op-amps andmany designs are featured in....
-
A phase-shift audio oscillator with excellent distortion characteristics thanks to "softened" diode limiting provided by the 1N914 and resistor divider and degenerated gain provided by the 68 ohm emitter resistor. For minimum distortion, increase the 68 ohm....
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The crystal radio gets its name from the galena crystal (lead sulfide) used to rectify the signals. A "cat`s whisker" wire contact was moved about the surface of the crystal until a diode junction was formed. The 1N34A germanium diode is the modern....
-
The basic two-transistor flasher shown below has found its way into dozens of applications due to its simplicity and versatility. Applications have included such diverse circuits as a micropower low battery indicator, a lightning detector, a off-line....
-
The familiar astable flip-flop circuit is a handy configuration for making flashers or generating squarewaves. Here is a typical alternating LED flasher with the LEDs in the emitters instead of collectors as is normally done. (There is another good reason to....
-
This magic lamp appears to be an ordinary frosted light bulb with a rather unusual characteristic. Whenever your finger is touched across the base threads and center contact the lamp magically lights! Without wires! It is a most effective illusion if you....
-
Here is a really simple game show timer designed with the beginner in mind! The power source is an ordinary 12 volt lantern battery or battery pack made up of C or D cells. The lamps may be ordinary flashlight bulbs; the prototype uses 750 mA Krypton types....
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-
The following circuit is an improved version of my original Lightning Detector designed to run on a 5 volt supply. The new circuit features a superior RF section with a single resonance near 300kHz and plenty of sensitivity. The potentiometer was eliminated;....
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The heart of the circuit is the two transistor flasher with frequency modulation applied to the base of the first transistor. When the pushbutton is depressed, the frequency of oscillation climbs to a peak and when the button is released, the frequency....
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The circuit below is similar to designs using unijunction transistors to generate the triggering pulse. The unijunction is replaced by a two-transistor "flasher" circuit that drives a pulse transformer. This type of circuit gives a wide range of control....
-
A simple circuit for sequentially flashing Christmas light strings or other similar low-power lamps. The socket symbols may be single bulbs or sockets for lamp strings. The load must be capable of operating from DC since the SCRs rectify the line voltage.....
-
This rain detector will give you a heads-up the instant it starts to rain, hopefully giving you time to close windows and bring in possessions. The battery-powered circuit draws virtually no current when the sensor is dry and the current consumption is low....
-
By gluing a standoff to the center of the cone, an inexpensive 2", 8 ohm speaker becomes a vibration sensor with a naturalresonance below 100Hz which is quite good. My implementation is shown below: After the epoxy cured, the speaker was hung in the middle....
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-
When a new computer modem enters the household, the demands on the home phone line skyrockets. The Internet surfer can use phone time on a par with the most talkative teenager. And the computer modem user can be quite sensitive about his privacy: simply....
-
VHF overtone crystals can be difficult to use due to the many frequencies at which the crystal is perfectly happy to oscillate. A typical 100 MHz, 5th-overtone crystal will oscillate at approximately 20 MHz, 60 MHz, 100 MHz, and even 140 MHz, not to mention....
-
Natural Radio" is simply radio noise with natural origins, mainly lightning, but also clouds of ions interacting with the earth`s magnetic field. Nearby lightning sounds like the familiar crackle heard on an ordinary AM radio but distant lightning produces....
-
This line voltage power controller interfaces a DC control voltage or microprocessor logic output to an AC load. By adding a filter capacitor to the input resistors, the circuit may be controlled by a duty-cycle modulated square wave with about 2. 5 volts....
-
-
These "ion chambers" are nothing more than a bare wire stuck through a hole into a metal can! No special gas or sealing is required. For best performance it is probably a good idea to add a desiccant to the inside of the can to keep the humidity low. (I....
-
A "video-digitiser" (also known as a "frame grabber") captures pictures from a TV set, camera, or video recorder, etc. , and forwards them to a computer for display, storage, or general manipulation. This document describes a home-built digitiser which....
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A "video-digitiser" (also known as a "frame grabber") captures still pictures frames from a TV set, video camera, or video recorder, etc. , and forwards them to a computer for display, storage, or general manipulation. This document describes the MarkII....
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This ultrasonic anemometer serves for the 2-dimensional capture of the horizontal components of the wind speed and the wind direction as well as the virtual temperature. On account of the high measuring rate this device is suited very well to capture gusts....
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I am posting here a circuit example for interfacing RF module using HT12E/D encoder decoder pair. The circuit attached here can be used to transfer data using the RF module. As I have explained earlier RF module mentioned here is having a single channel. So....
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This machine was near-and-dear to me as it was my first real computer, an Ohio Scientific Superboard II. In 1979 I got my machine, a 6502-based single-board computer with a whopping 8K of RAM and BASIC in ROM. The board was completely self-contained,....
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The example circuit is for an automatic animal feeder. When the animal pushes the switch the PICAXE microcontroller detects an input. The programme within the microcontroller then outputs at pin 6, energising a relay. This allows a second circuit to turn on....
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This is a discussion on Trying to build an Ambilight within the Electronics forums, part of the Tech Support Forum category. Hey there, I was recently looking at back lighting lights/LED`s for behind monitors. and I came across a thing called I was recently....
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The diagram is useful when replacing components since it shows component locations. It also identifies the wires by certain colors and identifies the specific component terminals that the wires are connected to. The most common types of diagrams are....
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The equation is: Putting some values to this equation, if a circuit has a resistance of 25 ohms (O) and a potential of 125 volts, the current that is drawn in this circuit would be 5 amps. This basic circuit will give you some understanding for the next....
-
The ammeter measures electric current. It may be calibrated in amperes, milliamperes, or microamperes. In order to measure current, the ammeter must be placed in series with the circuit to be tested (Figure 1). When an ammeter is placed in series with a....
-
The use of logic symbology results in a diagram that allows the user to determine the operation of a given component or system as the various input signals change. To read and interpret logic diagrams, the reader must understand what each of the specialized....
-
Motor starters generally fall into two categories: full-voltage or reduced-voltage. The choice of which type of starter to use depends on various factors, such as current-carrying capacity of plant wiring, ability of plant power supplies to absorb power....
-
An Astable Multivibrator is a switching circuit which switches its output on and off for a designed time period. This article also describes about its working. An Astable Multivibrator or a free running oscillator circuit is generally used to generate square....
-
Every cheap energy-saving lamp has a self-resonant voltage inverter inside. They are designed for low-power operation up to a few watts. Why don`t scale up the whole thing and replace the resonance circuit for generating the needed lamp voltage with the....
-
The emergency driver unit consists of a battery charger and electronic circuitry in one compact case. The batteries. Emergency lighting battery protection from over current and heat. Liquid. Crystal Display. (LCD) screen protection from short circuit and....
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-
CW operation up to 350mA from 2. 8. 6V supply voltage TTL modulation frequency up to 10KHz, with adjustable duty cycle. Rapid soft start after power-on. Simple power adjustment via the external resistor...
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10W HF linear amplifier circuit schematics free electronic circuits diagram wiring design plans schema DIY projects handbook guide tutorial schematico electrG³nico schG©matique diagrama esquemG tico projeto elektronisch schematisch schaltplan schematy....
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Quad comparators, type LM339. A flyback DC converter Done. Buck converter Step-up converter Done. that would consume several comparators and maybe there would be some nice LEDs, too. Then it hit me. A VU meter, big, beautiful, professional! From that moment....
-
The FlexiForce sensor acts as a force sensing resistor in an electrical circuit. When the force sensor is unloaded, its resistance is very high. When a force is applied to the sensor, this resistance decreases. The resistance can be read by connecting a....
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-
The great network of telegraph wires that once enfolded the nation like a cobweb has vanished just as surely as the spider`s handiwork is erased by a sudden sweep of the broom. " Please note that the information below is obsolete. Dial-up Morse is no longer....
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-
The light sources for mirror screws based on my work, consist of a dozen or more of high brightness LEDs, in colors or white, typically connected in parallel or series-parallel. Shown here are two amplifiers, capable of handling the full range of video....
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-
-
This page describes the development of electronics to display a monochrome video image on an electrostatic oscilloscope tube. This work is complementary to the Electron Optics page in the Experiments section. The ultimate goal is to display a moving video....
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The goal is to repeat the demonstrations showing that the electrical field energy developed by a well-designed Tesla coil transmitter can be detected by a sensitive, well-tuned Tesla coil receiver placed at a distance exceeding a few wavelengths. The present....
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Most people believe spark gap Tesla Coils can only be operated from high voltages - typically 4 - 15kV or more. But some unusual experiments can be made with as little as 240V - directly. Outside of very low frequency Pancake Coils, there is little practical....
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As per a recent study conducted by a US Government agency, Induction cooking is the most energy efficient cooking method compared to electrical heaters, gas and microwave ovens. There are other new cooking methods such as Halogen Cooking, find our article on....
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The motion detector circuit consists of two components, the emitter and the sensor/detector. The emitter is simply made up of an infrared emitting diode reverse biased to a 5-volt source. The sensor uses the MRD821 to detect the IR beam from the emitter. It....
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The circuit takes its input from the "zero-crossing detector", which provides it with a 0-to-1-to-0 pulse to "set" the R-S flip-flop and release the ramp circuit (A to Ramp) for it to start the ascent of the timing ramp...
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The following is a (hopefully clear) description of the final version of the trigger used and a circuit diagram for anyone wishing to construct their own. So bear with me while I fumble out some words The initial version of this trigger was a very simple....
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D1, D2, C1, and C2 double the AC line in, charging C3 through R1 to approximately 320 volts. R1 isolates the voltage doubler from the discharge capacitor C3 so that C1 and C2 do not participate in the flashtube discharge path. R2 and D3 form a 16-volt supply....
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Control the two digits representing minutes; this circuit includes two shift registers, 30 resistors, and 30 LEDs. (All told, a particularly simplecircuit, really. ) Here`s the schematic: As I came closer to completing the circuit design, it occurred to me....
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I wanted to add a security/sensor light near the main doorway that would run of 12 volts. You can buy 12 volt PIR sensors, but these are very expensive at over $50 each and designed for security systems. However you can pick up a 240v sensor light for less....
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Finally I have found a use for a bunch of DIP-style RF relays I acquired in a grab-bag from a discount electronics shop some time ago. These babies are sealed totally, and rf shielded with low contact capacitance. Perfect for VHF frequencies. They are 12....
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An idea came to me while watching the waves coming in from Malaspina Strait during a storm a couple of weeks ago. What if a person could hear the sounds of ocean waves as an audio recording Not the sounds you`d hear while walking on the beach, or even under....
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On the face of it the design of a Sound Square is simple, all you need are several Infra red beams across an opening and when ever you place your hand in it you break one of the beams. Simply detect which beam is broken and you know where about the square....
This is a phantom-powered FET preamplifier built into a 1/4" guitar cable, similar to the one on the Tillman site. There are only a couple of parts to the amplifier, so the difficulty was being able to trim and solder component leads to fit within the space....
I`ve had this old amp for about years, and friend of mine has volunteered to do the work to restore it. This is a Webster-Chicago 166-1 amplifier....
Alright, my 2204 won`t bias properly. I can`t get the tubes to idle at more than about 14 W (435 V * 33 mA cathode current). I popped a set of old Telefunkens in, but the wouldn`t go much over 10 W (440 V * 23 mA). They bias just fine in the middle of pot....
To my new bestest pals: Anyone with experience on the old Uni`s? Model 1221. Looking to switch her to el34`s from 6l6`s. Not the savviest in the tuber....
and the most likely problem with my wiring is ME. My apologies for the long post but I thought the more information and pictures I can provide the....
well i did a quick search, and i didnt find much on this issue my question is: Can anyone provide a diagram on how cruise control is wired up (94-....
This neat device replaces the input transistors and associated circuitry on one TO-220 style device. I had some driver boards made by my printed circuit house and decided that replacing the original driver board with the new PCB...
A densitometer is one of the most valuable tools a darkroom enthusiast can employ. Up until recently, however, densitometers were expensive and bulky. Furthermore, densitometers which would talk to your computer and calculate effective film speed, contrast....
This is an Astable Multivibrator Circuit to alternately flash two LEDs. The R and C Values determine the frequency and the 470 ohm collector load resistors set the current to about 20 miliamp, when the circuit is operated at 12Volts. Frequncy is about 1Cylce....
This small FM transmitter with a range of about 50 meters designed for connection to the USB port. With lots of mini-transmitters then you have a comprehensive, action-packed radio program. Due to the power supply via the USB port of a high frequency....
A speed closed loop control of DC motor using back emf sensing. Running a DC motor in one direction, just replace the LED with DC motor and remove the current limit resistor. Please note that motordirection reversal is not possible with this configuration.....
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....
A low cost high performance programmable home security system using few LDR`s as an input sensors. When above sensor(s) get triggered system may dial the user specified phone number (using build-in DTMF generator) and activate the high power audio alarm and....
A robot that operates when you give messages through your phone. Your mobile becomes your remote controller of your robot. Yes, it means if robot is in London, and you are in Mumbai, you can still control your robot. A super project for diploma students that....
This is a simple touch switch circuit, the 555 timer is configured as a one shot multivibrator that is triggered by touching the touch terminal. In this monostable mode, the timer generates a fixed pulse of about 4 seconds whenever the trigger voltage falls....
This is a simple alarm circuit which produces a musical tone when water or some conducting liquid comes in contact with the two sensor wires provided. The circuit is based on four transistors and one melody generator IC (M 3482). When water comes in contact....
This ultrasonic movement detector circuit uses a crystal locked circuit to get maximum performance from the ultrasonic transmitter. However, the detection circuit is different. think it is more sensitive. Check all the components against the parts list. It....
This wideband jammer simultaneously blocks all transmissions within a desired band typically by sweeping across the desired band to be blocked, starting at the lowest frequency and ending at the highest frequency of the band. For this purpose a linear....
A slot-loading Xbox 360 Slot loading, you know, like on a MacBook, where you put a CD or DVD in a thin auto-loading slot instead of pushing a button to make a mechanical tray slide out. The Xbox 360 has a tray-loader. The PlayStation 3, by comparison, uses a....
This circuit divides a 10 MHz reference to 1, 10, 100 or 1000 pulses per second. The pulse width is also jumper selectable with lots of choices. A sync input will align the pulses with an external pulse, say from a GPS receiver. The outputs are hiding over....
Using a similar circuit to the LF block converter, I`ve made a Schumann Resonance Converter that moves the near-DC signals up to around 2 kHz for an ordinary soundcard. Here`s the maiden run plot: It seems to work! The fuzzy lines below 30 Hz are due to the....
The purpose of this report is to provide background and findings or our senior project. We will discuss four steps that we used to complete our final project. The four steps of our project were research and development, design, construction, and test &....
The Amazing All-Band Receiver is basically a diode detector followed by a high-gain audio amplifier. This is not a multi-band receiver; it picks up everything at once! The detector uses a biased Schottky diode for excellent sensitivity and bandwidth; the....
The picture to the left is a high quality radio transmitter for the A. M. broadcast band. The transmitter legally operates with "micro-power" and will not set any distance records but, unlike simpler designs, the frequency stays put and the fidelity is....
Home-made antennas can greatly improve the performance of AM and FM radios, short-wave receivers, and scanners. If you are a talk-radio fan then experiment with the AM band antennas and you will be able to hear shows from all over the country with surprising....
The first choice is usually an integrated circuit designed for the purpose. A typical assortment can be seen on this National Semiconductor page. Discrete designs can also be built with readily available transistors or op-amps andmany designs are featured in....
A phase-shift audio oscillator with excellent distortion characteristics thanks to "softened" diode limiting provided by the 1N914 and resistor divider and degenerated gain provided by the 68 ohm emitter resistor. For minimum distortion, increase the 68 ohm....
The crystal radio gets its name from the galena crystal (lead sulfide) used to rectify the signals. A "cat`s whisker" wire contact was moved about the surface of the crystal until a diode junction was formed. The 1N34A germanium diode is the modern....
The basic two-transistor flasher shown below has found its way into dozens of applications due to its simplicity and versatility. Applications have included such diverse circuits as a micropower low battery indicator, a lightning detector, a off-line....
The familiar astable flip-flop circuit is a handy configuration for making flashers or generating squarewaves. Here is a typical alternating LED flasher with the LEDs in the emitters instead of collectors as is normally done. (There is another good reason to....
This magic lamp appears to be an ordinary frosted light bulb with a rather unusual characteristic. Whenever your finger is touched across the base threads and center contact the lamp magically lights! Without wires! It is a most effective illusion if you....
Here is a really simple game show timer designed with the beginner in mind! The power source is an ordinary 12 volt lantern battery or battery pack made up of C or D cells. The lamps may be ordinary flashlight bulbs; the prototype uses 750 mA Krypton types....
The following circuit is an improved version of my original Lightning Detector designed to run on a 5 volt supply. The new circuit features a superior RF section with a single resonance near 300kHz and plenty of sensitivity. The potentiometer was eliminated;....
The heart of the circuit is the two transistor flasher with frequency modulation applied to the base of the first transistor. When the pushbutton is depressed, the frequency of oscillation climbs to a peak and when the button is released, the frequency....
The circuit below is similar to designs using unijunction transistors to generate the triggering pulse. The unijunction is replaced by a two-transistor "flasher" circuit that drives a pulse transformer. This type of circuit gives a wide range of control....
A simple circuit for sequentially flashing Christmas light strings or other similar low-power lamps. The socket symbols may be single bulbs or sockets for lamp strings. The load must be capable of operating from DC since the SCRs rectify the line voltage.....
This rain detector will give you a heads-up the instant it starts to rain, hopefully giving you time to close windows and bring in possessions. The battery-powered circuit draws virtually no current when the sensor is dry and the current consumption is low....
By gluing a standoff to the center of the cone, an inexpensive 2", 8 ohm speaker becomes a vibration sensor with a naturalresonance below 100Hz which is quite good. My implementation is shown below: After the epoxy cured, the speaker was hung in the middle....
When a new computer modem enters the household, the demands on the home phone line skyrockets. The Internet surfer can use phone time on a par with the most talkative teenager. And the computer modem user can be quite sensitive about his privacy: simply....
VHF overtone crystals can be difficult to use due to the many frequencies at which the crystal is perfectly happy to oscillate. A typical 100 MHz, 5th-overtone crystal will oscillate at approximately 20 MHz, 60 MHz, 100 MHz, and even 140 MHz, not to mention....
Natural Radio" is simply radio noise with natural origins, mainly lightning, but also clouds of ions interacting with the earth`s magnetic field. Nearby lightning sounds like the familiar crackle heard on an ordinary AM radio but distant lightning produces....
This line voltage power controller interfaces a DC control voltage or microprocessor logic output to an AC load. By adding a filter capacitor to the input resistors, the circuit may be controlled by a duty-cycle modulated square wave with about 2. 5 volts....
These "ion chambers" are nothing more than a bare wire stuck through a hole into a metal can! No special gas or sealing is required. For best performance it is probably a good idea to add a desiccant to the inside of the can to keep the humidity low. (I....
A "video-digitiser" (also known as a "frame grabber") captures pictures from a TV set, camera, or video recorder, etc. , and forwards them to a computer for display, storage, or general manipulation. This document describes a home-built digitiser which....
A "video-digitiser" (also known as a "frame grabber") captures still pictures frames from a TV set, video camera, or video recorder, etc. , and forwards them to a computer for display, storage, or general manipulation. This document describes the MarkII....
This ultrasonic anemometer serves for the 2-dimensional capture of the horizontal components of the wind speed and the wind direction as well as the virtual temperature. On account of the high measuring rate this device is suited very well to capture gusts....
I am posting here a circuit example for interfacing RF module using HT12E/D encoder decoder pair. The circuit attached here can be used to transfer data using the RF module. As I have explained earlier RF module mentioned here is having a single channel. So....
This machine was near-and-dear to me as it was my first real computer, an Ohio Scientific Superboard II. In 1979 I got my machine, a 6502-based single-board computer with a whopping 8K of RAM and BASIC in ROM. The board was completely self-contained,....
The example circuit is for an automatic animal feeder. When the animal pushes the switch the PICAXE microcontroller detects an input. The programme within the microcontroller then outputs at pin 6, energising a relay. This allows a second circuit to turn on....
This is a discussion on Trying to build an Ambilight within the Electronics forums, part of the Tech Support Forum category. Hey there, I was recently looking at back lighting lights/LED`s for behind monitors. and I came across a thing called I was recently....
The diagram is useful when replacing components since it shows component locations. It also identifies the wires by certain colors and identifies the specific component terminals that the wires are connected to. The most common types of diagrams are....
The equation is: Putting some values to this equation, if a circuit has a resistance of 25 ohms (O) and a potential of 125 volts, the current that is drawn in this circuit would be 5 amps. This basic circuit will give you some understanding for the next....
The ammeter measures electric current. It may be calibrated in amperes, milliamperes, or microamperes. In order to measure current, the ammeter must be placed in series with the circuit to be tested (Figure 1). When an ammeter is placed in series with a....
The use of logic symbology results in a diagram that allows the user to determine the operation of a given component or system as the various input signals change. To read and interpret logic diagrams, the reader must understand what each of the specialized....
Motor starters generally fall into two categories: full-voltage or reduced-voltage. The choice of which type of starter to use depends on various factors, such as current-carrying capacity of plant wiring, ability of plant power supplies to absorb power....
An Astable Multivibrator is a switching circuit which switches its output on and off for a designed time period. This article also describes about its working. An Astable Multivibrator or a free running oscillator circuit is generally used to generate square....
Every cheap energy-saving lamp has a self-resonant voltage inverter inside. They are designed for low-power operation up to a few watts. Why don`t scale up the whole thing and replace the resonance circuit for generating the needed lamp voltage with the....
The emergency driver unit consists of a battery charger and electronic circuitry in one compact case. The batteries. Emergency lighting battery protection from over current and heat. Liquid. Crystal Display. (LCD) screen protection from short circuit and....
CW operation up to 350mA from 2. 8. 6V supply voltage TTL modulation frequency up to 10KHz, with adjustable duty cycle. Rapid soft start after power-on. Simple power adjustment via the external resistor...
10W HF linear amplifier circuit schematics free electronic circuits diagram wiring design plans schema DIY projects handbook guide tutorial schematico electrG³nico schG©matique diagrama esquemG tico projeto elektronisch schematisch schaltplan schematy....
Quad comparators, type LM339. A flyback DC converter Done. Buck converter Step-up converter Done. that would consume several comparators and maybe there would be some nice LEDs, too. Then it hit me. A VU meter, big, beautiful, professional! From that moment....
The FlexiForce sensor acts as a force sensing resistor in an electrical circuit. When the force sensor is unloaded, its resistance is very high. When a force is applied to the sensor, this resistance decreases. The resistance can be read by connecting a....
The great network of telegraph wires that once enfolded the nation like a cobweb has vanished just as surely as the spider`s handiwork is erased by a sudden sweep of the broom. " Please note that the information below is obsolete. Dial-up Morse is no longer....
The light sources for mirror screws based on my work, consist of a dozen or more of high brightness LEDs, in colors or white, typically connected in parallel or series-parallel. Shown here are two amplifiers, capable of handling the full range of video....
This page describes the development of electronics to display a monochrome video image on an electrostatic oscilloscope tube. This work is complementary to the Electron Optics page in the Experiments section. The ultimate goal is to display a moving video....
The goal is to repeat the demonstrations showing that the electrical field energy developed by a well-designed Tesla coil transmitter can be detected by a sensitive, well-tuned Tesla coil receiver placed at a distance exceeding a few wavelengths. The present....
Most people believe spark gap Tesla Coils can only be operated from high voltages - typically 4 - 15kV or more. But some unusual experiments can be made with as little as 240V - directly. Outside of very low frequency Pancake Coils, there is little practical....
As per a recent study conducted by a US Government agency, Induction cooking is the most energy efficient cooking method compared to electrical heaters, gas and microwave ovens. There are other new cooking methods such as Halogen Cooking, find our article on....
The motion detector circuit consists of two components, the emitter and the sensor/detector. The emitter is simply made up of an infrared emitting diode reverse biased to a 5-volt source. The sensor uses the MRD821 to detect the IR beam from the emitter. It....
The circuit takes its input from the "zero-crossing detector", which provides it with a 0-to-1-to-0 pulse to "set" the R-S flip-flop and release the ramp circuit (A to Ramp) for it to start the ascent of the timing ramp...
The following is a (hopefully clear) description of the final version of the trigger used and a circuit diagram for anyone wishing to construct their own. So bear with me while I fumble out some words The initial version of this trigger was a very simple....
D1, D2, C1, and C2 double the AC line in, charging C3 through R1 to approximately 320 volts. R1 isolates the voltage doubler from the discharge capacitor C3 so that C1 and C2 do not participate in the flashtube discharge path. R2 and D3 form a 16-volt supply....
Control the two digits representing minutes; this circuit includes two shift registers, 30 resistors, and 30 LEDs. (All told, a particularly simplecircuit, really. ) Here`s the schematic: As I came closer to completing the circuit design, it occurred to me....
I wanted to add a security/sensor light near the main doorway that would run of 12 volts. You can buy 12 volt PIR sensors, but these are very expensive at over $50 each and designed for security systems. However you can pick up a 240v sensor light for less....
Finally I have found a use for a bunch of DIP-style RF relays I acquired in a grab-bag from a discount electronics shop some time ago. These babies are sealed totally, and rf shielded with low contact capacitance. Perfect for VHF frequencies. They are 12....
An idea came to me while watching the waves coming in from Malaspina Strait during a storm a couple of weeks ago. What if a person could hear the sounds of ocean waves as an audio recording Not the sounds you`d hear while walking on the beach, or even under....
On the face of it the design of a Sound Square is simple, all you need are several Infra red beams across an opening and when ever you place your hand in it you break one of the beams. Simply detect which beam is broken and you know where about the square....
