Meters Circuits
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A few months ago as I was surfing on the net, I saw an oscilloscope based on PIC18F2550 microcontroller and a KS0108 controller based graphical LCD. That was Steven Cholewiak's web site. I had never seen before so amazing microcontroller-only oscilloscope..... -
The circuit is powered by the receiver's pack, the current drain is low, specially if compared to drain of servos. U1a VZ2 and Q1 are the CURRENT source of the sensor VZ2 is temperature compensated, use the listed component except for Q1 there you can use.... -
Probably the best advantage is its very small size and the fact that it can run off the power supply of the circuit being tested. Although it has a low frequency range, it can still be used for most circuits. Its poor resolution will still allow for most.... -
This design uses a Motorola MPX4115 Silicon Pressure Sensor, a Dallas Semiconductor DS2438 Smart Battery Monitor (to perform 1-Wire analog to digital conversion), an operational amplifier, a voltage regulator, a diode, and several resistors and capacitors..... -
In this circuit, a simple calculator, in conjunction with a COB (chip-on-board) from an analogue quartz clock, is used to make a telephone call meter. The calculator enables conversion of STD/ISD calls to local call equivalents and always displays current.... -
A simple test circuit to fault find audio and radio equipment. Can be used to inject a square wave signal, rich in harmonics, or used with headphones as an audio tracer. A single pole double throw sitch is used to switch between inject and trace modes. The.... -
Sometimes when experimenting with different soundcards and MIDI interfaces it is useful to see if there is some data going in MIDI interface. This can be easily tested with this adapter, which converts the midi signals to visible light pulses. Just the.... -
The design presented here works by applying a 50kHz, 200mV square wave to the capacitor under test, in series with a 10 Ohm resistor. The AC voltage appearing across that resistor is measured and displayed on a meter. So the whole thing is nothing else than.... -
The general (and very basic) principle of operation is shown in Figure 1. The test signal is simply derived from the mains, and is a sinewave at 50 or 60Hz. In most locations, the sinewave will be distorted, but this barely matters. With nothing connected to.... -
Testing loudspeakers is covered in some detail in the passive crossover article (see Design of Passive Crossovers), but it is irksome at best to have to fiddle about with clip leads and components lying all over the workbench. This simple project is.... -
This probe is useful for any low level RF work, and simply connects to your multimeter. The voltage shown will not be accurate, since this is a rectifier probe, but the measurements are good enough for you to be able to determine where the RF stops, or if a.... -
The design objective was to produce an hFE tester with switched collector currents for the DUT (Device Under Test) covering a range suitable for the selection and matching of output transistors for amplifiers such as the JLH Class-A, ESP DoZ etc. The tester.... -
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.... -
The PIC Microchip Processor must be programmed before it will function as a Volt & Amp meter. There are many internet sites and PIC programmers that you can use. I used a Microchip MPLAB ICD 2 during the project. You might need to made changes to the circuit.... -
Because it uses few parts, a printed circuit board is not necessary; components can simply be soldered to one another. However, a box is desirable for operating convenience. The case and aerial from a discarded toy walkie-talkie was used in the prototype.... -
The instrument used to measure battery capacity. The battery may be charged to any current in the range 0-3 A. The load current may be constant, may change over time or even break off completely. Unloading stops when the battery voltage drops below the set.... -
The device serves to quickly establish the status of an indicative power cells. I built it for his children, so they can determine the degree of self-discharge batteries in a variety of toys. WAS tester designed to test the fast primary (zinc, alcaline).... -
LM3914 Dot Bar Display Driver LM3914 is a monolithic integrated circuit that senses analog voltage levels and drives 20 Led stereo Vu Metre Devresi PCB Circuit LM3914 10 leds stereo vumeter circuit diagram of Eagle PCB drawing of eagle .. -
This device was designed to replace the original digital clock in a Fiat Ducato 1992-1994, mounted just above the inside rearview mirror. The original clock is not very accurate, only displays time and is sensitive to interference (e. g. from Xenon.... -
This circuit is based around the PIC16LF1937 microcontroller. This chip is actually a small computer contained in a single chip, including RAM memory, EEPROM, I/O ports, CPU and so on. When you buy this chip, it comes empty with no program on it. You have to.... -
This project demonstrates a number of aspects of the PIC16F687 microcontroller, like: ultra low power wake up, serial communications, nanowatt technology etc. The device can be used for different purposes. For example: measuring the content of a rain water.... -
IC4 is a counter/oscillator combination and is the key element in the circuit. The oscillator outputs its AC signal on pin 7. This signal is lead (through voltage divider R3/R4) to pin 3 of IC5 (multiplexer IC) which is used as an input. The same signal is.... -
This circuit is a digital voltmeter with LED display. It`s ideal to use for measuring the output voltage of your DC power supply. It includes a 3. 5-digit LED display with a negative voltage indicator. It measures DC voltages from 0 to 199. 9V with a.... -
The MOSFET input of the CA3140 makes it ideally suited for use in a high impedance DC voltmeter. Switch S1 is the range selector. The input impedance is limited to 10M by the resistors used in the voltage divider, but this is still a very acceptable value..... -
This is extremely simple to build PIC Temperature meter that allows to measure temperature in two different locations at the same time. Never before such a useful and powerful circuit could be built with so little components and yet provide endless.... -
The ESR Meter is basically an AC Ohmmeter with special scales and protective circuitry. It provides a continuous reading of series resistance in electrolytic capacitors. It operates at 100 kHz to keep the capacitive reactance factor near zero. The remaining.... -
Building a serial voltage meter to measure from 0 to 5 volts DC is actually pretty easy. Using MeLabs PicBasic, and Microsoft`s Visual Basic Version 5 Pro. You need Visual Basic Pro version because you will have to use Basic`s MSComm control. This control is.... -
Here is a simple 2. 4 GHz SWR meter which can be easily found, which is based around surplus microwave hardware. The main component is a MECA -20/-20 dB Directional Coupler which has a frequency range of approximately 700 MHz to 2. 5 GHz. This particular....
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.....
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