Logic Circuits
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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 buttons. This simple circuit would be a great touch to any home audio project. Using a dual polariity.... -
I built this cable for my Casio QV-200 digital camera, it should work for many Casio models. It`s basically a inverting buffer/converter to/from RS-232 voltage levels from/to CMOS levels. Why Casio didn`t put this inside the camera like everyone else does is.... -
Both ac and dc motors in modern industrial systems often receive their control from PLCs (programmable-logic controllers) in a control room safely away from the process. If an operator must manually set the motor speed while observing the process, the.... -
Current-limit switches are virtually ubiquitous in system controls. They provide a safe means for regulating the current delivered to a load circuit. The switches allow the load current to increase to a programmed limit but no higher. Typically, the current....
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One of the requirements that is easily overlooked is the need to identify your station during your video communications. From what I have seen, some R/C wireless video users are neglecting to broadcast their ham radio call sign. Essentially, USA hams must do....
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Digitally programmable current sources that feature automatic trimming and retain the setting despite power-down cycles are useful in applications such as RF- and laser-communications drivers. The circuit in Figure 1, for example, is particularly suited for....
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Crosstalk from digital data signals into the clock signal of a data-conversion system can cause hard-to-diagnose problems. This obscure problem is different than the crosstalk from digital data signals into the analog signal path, which was the subject of....
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The digital delay presented here is expected to be sufficient for most applications, and although the delay is fixed at 20ms, this is the most usable delay period. This is the equivalent of being about 7 metres away from the rear speakers, and they will have.... -
The circuit is a simple, but accurate Digital Guitar Tuner. It samples the input, which can be directly from the mics of an electric guitar, or from a microphone, it you`re using an acoustic guitar. It can ofcourse also be used for tuning other instruments..... -
Hardware is located in a small box slipped in pants` pocket and the display is conceived in the following manner: the leftmost display D2 (the most significant digit) shows 0 to 9 Km. and its dot is always on to separate Km. from hm. The rightmost display D1.... -
This circuit measures the distance covered during a walk. Hardware is located in a small box slipped in pants` pocket and the display is conceived in the following manner: the leftmost display D2 (the most significant digit) shows 0 to 9 Km. and its dot is.... -
What is the effect of digital signal bits cross-talking into the analog section of a data-conversion system? There is a lot written into the data sheets of ADCs and DACs on how to minimize it. But, when asked what is the result, most laymen have the insight....
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This design was never completely finished, so consider it to be in the very early experimental stage. I don`t sell kits, programmed PLD`s, or provide support for this project, and I will never be published. But if you want to take a bash at making it.... -
Many designs require FIFO elastic buffers to form a bridge between subsystems with different clock rates and access requirements. However, in some applications, you need FIFO buffers for data conversion. One example is the case in which you need to connect....
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I have had this project hanging around for ages and have tried to submit it for publication without much enthusiasm so I will make everything available here for the individual constructor. The complete Pascal source code for the compiler program is available.... -
You may find that there are too few, if your power is very noisy (as can happen in a car environment) it may help to place a 0.1uF and/or 10uF capacitor before and/or after the voltage regulator. At the moment I`m not using these but at this point I`ve only.... -
A typical device that requires less than 5v and draws less than 25mA is an LED. A LED must be supplied with an exact voltage for it to operate correctly. Because it requires LESS than 5v, a dropper resistor (current limiting resistor) must be included in.... -
This page features a replacement circuit for the LM3909 LED Flasher / Oscillator using discrete components. The circuit is functionally the same as the integrated LM3909 but has a minor variation of the components used. Naturally the circuit will not be as.... -
The circuit in Figure 1 provides not only a complementary drive signal but also a deadtime delay on both rising and falling edges. The high-speed inverter gates use IC1, a 74HC04 CMOS circuit, and 1N5819 Schottky diodes D1 and D2. The 74HC04 inverter....
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This logic probe uses a single CMOS IC and shows three logic conditions, High, Low and Pulsing. In addition if the probe input is neither hi or low (the high impedance state of tri-output logic ic`s) then no LED`s will light. Power from the logic probe is.... -
The 5 volt regulated power supply for TTL and 74LS series integrated circuits, has to be very precise and tolerant of voltage transients. These IC`s are easily damaged by short voltage spikes. A fuse will blow when its current rating is exceeded, but.... -
This project is designed to program the 8-pin PIC12c508A and 18pin PIC16F84 microcontroller chips to support the projects we have designed, however it will also program a number of other 8-pin & 18-pin microcontrollers and the full list can be seen when.... -
Many embedded-microcontroller applications require generation of analog signals. An integrated or stand-alone DAC fills the role. However, you can often use PWM signals for generating the required analog signals. You can use PWM signals to create both dc and....
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A digital storage oscilloscope (DSO) is a very important piece of test equipment that can do the jobs that a normal CRO just can`t handle. Such as capturing single shot and widely spaced waveshapes, and looking at non repetitive.... -
The logic designer is filled with features. It would not be possible to list all the possible combinations of the unit as the various building blocks on the board can be interconnected to obtain a wide variety of counting and testing stages. You will be able.... -
This LOGIC PULSER capable of delivering pulses of various compositions, to any type of circuit you wish to test. Basically it is designed to complement the LOGIC PROBE and can be used in situations where the LOGIC PROBE is not so effective. It is an.... -
The circuit shown will convert logic level voltages to and from RS232 serial voltages levels. For basic serial comms between a Microchip PIC and a PC or other device you generally only need to connect the Gnd, Txd and Rxd lines. This little circuit....
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Here's another daft yet interesting PIC12F675 idea I came up with. When I wanted to show someone how logic gates worked I could only find a NAND gate which wasn't very handy for demonstrating AND's OR's, NOR's and ExOR's. I also wanted to have a play with....
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This circuit is a Logic Probe. It indicates the logic state of the node of any TTL logic circuit. To do that, we have to supply the probe with the same power of the circuit that we want to analyse: same Vcc and same GND. To check the logic level, we must.... -
This project is based on a probe logic states, capable of measuring levels from TTL (5v) to state levels of PLC's (24v). For this we have employed the use of the PIC 12F683 microcontroller, which by its nature is capable of operating at low voltages, in this.... -
Simplified logic checker. Logic voltage levels have the ability to display LED (Of course I (^_^;)." H "in the LED is green," L "and red LED lights, and so both the open and goes out . But not only that was put on the ability to detect narrow pulses. In.... -
When testing circuits with a logic probe, it is sometimes difficult to watch the LEDS on the probe to determine the logic state. With this probe the logic states are audible. This probe is designed for TTL circuits only but could be modified for CMOS. The....
New Circuits
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This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of.... -
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is.... -
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to.... -
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This.... -
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the.... -
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,.... -
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the.... -
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power.... -
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
Popular Circuits
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