Repository-circuits
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The 555 can be almost any type, they are all pin-compatible. Although some CMOS types may not have enough power to drive the transistor, in that case use an ordinary 555. C1`s working voltage should be increased to 25V if you decide to go with a 12V power.... -
As it has already been stated the circuit consists of an ultrasonic transmitter and a receiver both of which work at the same frequency. They use ultrasonic piezoelectric transducers as output and input devices respectively and their frequency of operation.... -
The loop can be any type of hookup wire, with a maximum resistance of about 90K. Using very thin wire (40AWG, for example) will make a very sensitive trip wire, but will shorten the distance it can be strung due to the high resistance... -
Alphanumeric LCD displays have become very popular for microcontroller applications because they can add a lot to a project in a variety of different ways. A text message giving the user instructions as well as feedback can make the application seem much.... -
This schematic is provided in the hope that it will be useful, but without any warranty, not even a warranty of merchantability or fitness for a particular purpose. The address bus in this schematic is connected in an unusual way, which is optimized for.... -
A basic circuit of the 89C2051 shown here can be made easily using point-to-point soldering with a universal PCB. Use an ordinary 20-pin socket, do not use a circle-pin socket. D1 is a small dot LED. U2 can be either 7805 or 78L05. U3 is optional for.... -
The MCU is ATMEL 89C4051 CMOS Microcontroller having 4kB code memory, 128 bytes On-chip RAM and 8-bit Port1 and Port3. The A/D chip is HARRIS CA3162, 3-digit DVM. The A/D converter employs dual-slope integrator providing 10Hz sampling rate. Digital output.... -
The Saver V5. 0 runs simple clock emulation program, turns a night light on and off with preset time, say 19:00 to 22:00 everyday. The design features low cost, easy installation, no battery backup and no EMI. The AT89C2051 uses external oscillator generated.... -
This is my long history the device that controls my home`s night light, air-conditioner, etc. The device is a Miniature Real-time Controller. The circuit uses only three chips, a 89C2051, DS275(or MAX232), and 74LS07 open collector driver. The scheduler for.... -
M1 is a stepper taken from an old disk drive. There are five pins, i. e. , common, coil 1, 2, 3 and 4. Resistance measured between common pin and each coil is about 75 Ohms. Driving current for each coil is then needed about 60mA at +5V supply. A Darlington.... -
The schematic show that the AccelR8 only uses 3 IC`s. An AVR 8515 microcontroller do the calculation work and controls the other circuits. An MAX603 controls voltage and power-on/power-off. And the chip that makes it all possible, the ADXL202 from Analog.... -
The Atmel Flash devices are ideal for developing, since they can be reprogrammed easy and fast. If you need more code space for your application, particularly for developing 89Cxx projects with C language. Atmel offers a broad range of microcontrollers based.... -
This is a "beta release" schematic. Use at your own risk The idea is to add this circuitry to a board with already has ram at 2000 and an 82C55 I/O chip to provide ports A, B and C. Warning: not shown here is a memory mapping trick which is described below..... -
This single sided proto board provides an economical solution for developing and testing the projects around Atmel 20 pin series u-controllers (89Cx051 & AVR). Figure 1 shows the circuit diagram of proto board. All port connections are available for user.... -
This ISP Programmer can be used either for in-system programming or as a stand-alone spi programmer for Atmel ISP programmable devices. The programming interface is compatible to STK200 ISP programmer hardware so the users of STK200 can also use the software.... -
A method of determining altitude is by the use of barometric pressure; however, it is not done without difficulty. The relationship of pressure vs. altitude is not a linear one, it is actually a fairly complex one, which the army came up with in the 1930`s..... -
Various embodiments of the BB metal detector have been published, and it has been widely described in the press as a new genre. Instead of using a search and a reference oscillator as with BFO, or Tx and Rx coils as with IB, it uses two transmitters or.... -
This simple circuit uses a 741 op-amp in differential mode as a continuity tester. The voltage difference between the non-inverting and inverting inputs is amplified by the full open loop gain of the op-amp. Ignore the 470k and the 10k control for the.... -
This tester is designed to locate stray electromagnetic (EM) fields. It will easily detect both audio and RF signals up to frequencies of around 100kHz. Note, however that this circuit is NOT a metal detector, but will detect metal wiring if it conducting ac.... -
This circuit is the result of Andy Collinson research. He has used a photodiode, SFH2030 as an infra red sensor. A MOSFET opamp, CA3140 is used in the differential mode to amplify the pulses of current from the photodiode. LED1 is an ordinary coloured led....
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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