Meters Circuits
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This simple to construct water fishing thermometer circuit is intended to be used in sports applications like for example a fishing contest. A sensor measu.... -
This sound wattmeter uses a row of colored LEDs as a scale to show the relative power output of your amplifier in watts. It is easy to be inserted into the speaker box. All you need is to hook a supply voltage to it. The value of R1 depends upon the.... -
Circuit consists of an oscillator with variable frequency, a divided frequency and measurement stage. The Oscillator is based on a inversor from a 74HC14 and generates a frequency f inversely proportional to the Cx placed between terminals. During a half.... -
SWR or standing wave ratio is the ratio of the amplitude of a partial standing wave at an antinode (maximum) to the amplitude at an adjacent node (minimum).... -
A sensitive and reliable rf field strength meter is an invaluable instrument in amateur radio and in radio controlled model area. A field strength meter is used to align an antenna to get the best possible gain, to determine the transmitting range of radio.... -
This digital thermometer circuit diagram uses a common 1N4148 diode as the temperature sensor. The temperature coefficient of the diode, -2 mV/°C is ex.... -
This digital DIY tachometer for bikes uses two reed switches to get the speed information of the bicycle. The reed switches are installed near the rim of the wheel where permanent magnets pass by. The permanent magnets are attached to the wheelspokes and.... -
A Simple LED Voltmeter to Monitor the charge level in Lead Acid Battery or Tubular battery. The terminal voltage of the battery is indicated through a four level LED indicators. The nominal terminal voltage of a Lead Acid battery is 13. 8 volts and that of a.... -
The circuit featured here is very useful to save you from burning your tongue. The coffee thermometer is composed of a voltage regulator, a temperature to voltage converter, a comparator and two LEDs. Roughly described, the circuit works this way: if the.... -
This LC meter circuit can measure coils and capacitors. When Lx or Cx is connected in the circuit the oscillator frequency will decrease and this decrease is measured by a frequency-voltage converter build with T3 and T4. To adjust this lc meter circuit with.... -
This sensitive touch potentiometer is based on IC1 (CA3130), one operational amplifier with a high input impedance. When the finger touches Se1 sensor, C2.... -
This sound level meter circuit can be used to control the intensity of a sound recording or in a disco. It has 5 measurement domains between 70 and 120 dB;.... -
This is a take-off on Mr. Marian s ""Simple Micro Ampere Meter Circuit"" that utilizes active circuitry and an analog meter to make sensitive DC current meas.... -
An DIY RF decibel (or power) meter is an indispensable instrument in any radio workshop. Unfortunately, accurate, wideband models are fairly expensive, and.... -
UHF indicator or wavemeter is some kind of device that measures frequencies and determines LC circuit frequecy resonance. This device does not need to radiate. The oscillator is build with T1 and T2 (2 x BF494) and can be adjusted with C1 and Lx. The Lx coil.... -
Some experts` think that SMFs may affect the physical well-being of people. If you believe that these experts are right, the magnetic-field meter described will help you find sources of SMFs and determine their strength. These findings may help you reduce.... -
The CA3189 IC integrates a symmetrical limiter, a phase demodulator, an audio amplifier, and a logarithmic detector-amplifier. The logarithmic detector-amplifier is the most interesting part of the IC for the above featured circuit. It can be used to enhance.... -
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 local call-meter.... -
an easy to build, but nevertheless very accurate and useful digital voltmeter. It has been designed as a panel meter and can be used in DC power supplies or anywhere else it is necessary to have an accurate indication of the voltage present. The circuit.... -
Understanding of the concept of "Hysteresis" is very important. When generally considered, this phenomena gives rise to losses seen in the dielectric of a capacitor or lamination of a transformer, these can be seen in the form of heat(emission of infrared.... -
Normally, digital speedometers are found only in luxury cars and high-end motorbikes. Even if your motorbike has a mechanical speedometer, what will you do when it gets damaged? First, It is a digital Speedometer which shows the speed and Kilometers in.... -
Battery Volt Meter Circuit Diagram. Here is an ideal circuit to monitor the voltage level in Lead Acid or Tubular battery. It gives four LED indications to give the voltage level between 9 volts and 14 volts .. -
In the 20. 5X10. 5 cm rectangular piece, there is a hole of diameter 1. 5 cm to attach the motors for movement of the ROBO CAR with the help of nut and bolt system. The caster wheels used in the DTMF based ROBO CAR is made up from the cast iron material and.... -
Microcontroller Based Accelerometer Project. Just as a speedometer is a meter that measures speed, an accelerometer is a meter that measures acceleration .. -
i have this project which requires us to make a digital speedometer and odometer and used AT89S52. I have tried it on Proteus (ISIS) simulator and is actually working .. -
A circuit of LC meter (inductance & capacitance meter) which is base on PIC16F84A microcontroller but i have no code for this IC, i place circuit diagram of the project, so please help me... -
This is a wide band signal strength meter circuit which responds to small changes in RF energy, designed to be used for the VHF spectrum and will respond to AM or FM modulation or just a plain carrier wave. This circuit measures radio field strength by.... -
The multimeter should be set to the lowest dc volts range for maximum sensitivity. This is normally 200mV DC for most meters. The circuit works well at VHF (around 100MHz) and was quite pleased with the results. L1 was 7 turns on a quarter inch former with....
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
This reflex radio project was inspired by Robert Bazian 's design. His reflex radio is the...
False alarms produced by semiconductor failure are impossible with this burglar-alarm circuit...
If the battery voltage exceeds about 11 V, current flows through R1, D1, and R2. The voltage...
Our reader Andrea (andrea[dot]perugia[-at-]gmail[dot] com) sent his circuit to us, and he creates...
The Photovore`s brain is built around two NAND-gates and six inverters, four elements each in two...
Metal detector using avr tiny13. i m planning to use 555 ic to energize the coil and giving this...
The ZN414 IC contains an entire automatic gain controlled AM receiver in a small three pin...
This circuit is useful to detect microwave (gigahertz signal) sources like microwave oven,...
The circuit below uses a CMOS dual D flip flop (CD4013) to toggle a relay or other load with a...
The RF engineer sometimes has to look for an instrument that will check a low frequency quartz...
An LC oscillator is driven by pulses which are generated by a 555 IC based oscillator. LC...