Meters Circuits
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This article describes a 2 meter amplifier capable of running 25-30 watts output. More than 35 amplifiers have been procured at a cost of less than $50 each in these quantities. Photo A shows the final version of the circuit board; the completed amplifier is.... -
This simple VU Meter may be used in variety of projects. Since real electro magnetic type VU Meters are no longer available or too expensive, I decided to make this one using LM3914 and 10 LEDs, which I can use in my other projects... -
This nifty sound level meter is a perfect one chip replacement for the standard analog meters. It is completely solid state and will never wear out. The whole circuit is based on the LM3915 audio level IC and uses only a few external components... -
The current task is to design the schematic layout, design the PCB layout, and generate the. contractor with RF schematic design and PCB layout experience Please review the block diagram in the attached. antenna will be connected to the RFOUT coax and an RF.... -
Hi all, i`ve recently bought the dantimax thatmic pre amp and i was wondering if anyone could point me in the right direction to install a vu meter.... -
This document describes a simple SWR-meter suitable for long and medium waves bands (137 and 500kHz). The design is nothing new and very similar to common short wave meters, but it has been designed to work with low frequencies. The majority of amateur radio.... -
A VU-meter is a very common instrument usually installed on audio Hi-Fi amplifiers and is used to show the instantaneous power provided to the speakers. It is usually connected at the output of the amplifier, in parallel with the speaker. The term "VU".... -
This is a quick how-to guide for making a stereo VU meter using the LM3915/LM3916. The LM 3916 is an integrated circuit (IC) that takes analog voltage levels and drives 10 LEDs, LCDs, or vacuum fluorescent displays to represent digital voltage levels just.... -
The meter came from eBay, and has a 1 mA full scale movement. It was already marked 0 to 100. I simply removed the original scale, scanned it, and added the "% NETWORK" markings over some of the original ones with an image editor. I then printed the new.... -
A well tuned antenna system works like a dummy load, i. e. the SWR is 1. 2:1 or below but the hunting range is low. What`s wrong Insufficient radiation How to know that Yes, this is what the article about. You can measure the effective radiation using a.... -
Calibrating the Smiths electronic tachometer some time ago when I realized that my tach was completely out of calibration. I used a technique similar to the one described in Tom Ballous 1975 Tech Tip to calibrate my tach at about 1200RPM using my dwell/tach.... -
This circuit is a Digital Radar Speedometer. It allows us to evaluate the speed of any object moving, especially cars and other vehicles. The speed is calculated in kilometers per hour (KPH). Its display has three digits. This radar works with the laser.... -
This circuit is intended for precision centigrade temperature measurement, with a transmitter section converting to frequency the sensor`s output voltage proportional to the measured temperature. The output frequency bursts are conveyed into the mains supply.... -
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.... -
In the circuit, a quad voltage comparator (LM339) is used as a simple bar graph meter to indicate the charge condition of a 12 volt, lead acid battery. A 5 volt reference voltage is connected to each of the (+) inputs of the four comparators and the (-).... -
This is a similar circuit to the above and provides a 4 LED bar graph indicating the voltage of a common 3.6 volt Lithium - Ion recharable cell phone battery. The reference voltage is provided by a TL431 programmable voltage source which is set to 3.9 volts.... -
You can`t expect great performance from such a simple detector-based meter. Sensitivity is just adequate enough to get a basic idea of the power that your transmitter is capable of.... -
A milliamp meter can be used as a volt meter by adding a series resistance. The resistance needed is the full scale voltage reading divided by the full scale current of the meter movement. So, if you have a 1 milliamp meter and you want to read 0-10 volts.... -
The ICL7107 is a 3 1/2 digit LED A/D convertor. It contains an internal voltage reference, high isolation analog switches, sequential control logic, and the display drivers.... -
This circuit is intended for precision centigrade temperature measurement, with a transmitter section converting to frequency the sensor`s output voltage, which is proportional to the measured temperature. The output frequency bursts are conveyed into the.... -
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.... -
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.....
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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