This probe makes possible relative measurements of rf voltages to 200 MHz on a 20,000 ohms-per-volt multimeter..
This circuit will allow a multimeter to display the positive or negative peaks of an incoming signal. A 741, JC1, is used in the noninverting mode with R1 defining the input impedance. D1 or D2 will conduct on a positive or negative peak, charging C2 until the inverting input is at the same de level as the incoming peak. This level will maintain the voltage until a higher peak is detected, then this will be stored by C2. Another 7 41, IC2, prevents loading by the.....
The current range in multimeters, particularly the more inexpensive ones, is restricted by the load limits of the internal..
The DMM-ProfiLab-Software allows you to develop any measuring technology projects based upon digital multimeters: A simple curve plotter or a complex measuring technology project. By the integrated support of relay cards you are not only able to read and process measurement values, you can even react. You can create complete control systems! And for all this you dont have to write a single program-line. You create your project just like drawing a wiring diagram. Simply add.....
You can use a multimeter with capacitance-measurement capability to measure the length of wire or cable to an open circuit. The capacitance of a pair of wires (or a wire to a shield) is directly proportional to the length of the wire. If you know the capacitance per foot of wire, then you can calculate how far it is to the open circuit...
The µCurrent is in many cases also able to improve upon your meters current range accuracy by using your meters more accurate mVDC or mVAC voltage ranges instead to display the DC or AC current. With AC the frequency response extends flat up to 10KHz, but THD increases substantially above 2KHz. Still a very respectable AC response range, surpassing that of many meters on current and voltage ranges. Typical accuracy of the µCurrent itself is better than 0.2% on the µA.....
This circuit is designed to provide an inexpensive way to to create a High Impedance Voltmeter while making use of an inexpensive analog or digital multimeter. When measuring voltages in high resistance circuits the resistance of the voltmeter itself has an effect on the circuit. For example if the voltage across a 1 megohm resistor is measured with a voltmeter that has an internal resistance of 1 megohm then the total resistance in that part of the circuit is effectively.....
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 improvement over a multimeter in that it has an audible output and is NOT triggered when measuring across a diode. Don`t underestimate the importance of this item of test equipment. It is needed to properly test and locate a.....
For the regulation it needs a voltmeter (with needle better) and charge 50W/5W. Connect charge 50W in the place of aerial, with the voltmeter in the exit voltmeter. Be supplied the transmitter with + 12V. It will be supposed we have consumption between 0,7-1A. With a screwdriver we regulate the core of inductor L1/L2 and later the variable C6 until we see the biggest tendency. We connect the microphone and speaking we observe the clue in the multimeter. ..
This Field Strength Meter is simple and also quite sensitive. It uses an ordinary digital voltmeter to measure RF signal strength up to a few hundred MHz. 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 ferrite slug...
CallID Unit based on Motorola MC68HC11A1P & MC145447P chips compatible with the standard protocols. if you got a multimeter and a phone you can start testing. Check the voltage across the pair, should be 48VDC in US, 60VDC in Europe. Place a 600 ohm resistor, 5W across the pair and measure the current should be 20 to 40mA (holding current) While on-hook the Ring will have a negative voltage and the Tip will be grounded through equipment at the Central Office UNLESS.....
This audio bandpass filter is useful for amplification and filtering of weak AM TV video carriers. For example, a DFM (digital frequency audio multimeter) may have insufficient input sensitivity for measuring extremely weak SSB TV video audio signals. By using the 20 Hz filter to peak the wanted carrier, the DFM will display the carrier frequency. Another possible application for this filter is increased amplification and reduced bandwidth of weak BCB heterodyne AM.....
The LED power Meter is a simple RF detector using diodes to charge a capacitor. The voltage developed across the capacitor is indicated by a multimeter set to a low voltage range. The circuit is soldered together without the need for a PC board, as can be seen in the diagram below and paper clips are used for the positive and negative terminals of the multimeter. It will only take a few minutes to put this circuit together. The power from the output of an FM transmitter.....
This multimeter was designed to measure output voltage and current in a PSU, where the current sense shunt resistor is connected in series with load at the negative voltage rail. It needs only one supply voltage that can be acquired from main PSU. An additional function of the multimeter is that it can control (switch on and off) an electric fan used to cool the main heatsink. The power threshold at which the fan switches on can be adjusted using One Touch Button Setup......
The LTC®2400 is the industrys first No Latency TM ADC that combines automatic offset and full-scale calibration, an internal oscillator, a sinc4 digital filter, and serial I/O to yield a 24-bit ADC with 1.5µVRMS input noise and singleshot conversion time architecture. It is the ideal A/D converter for temperature measurement and high effective resolution instrumentation applications, such as digital multimeters...
Using a modern multimeter to measure current can sometimes be difficult. Many of these meters will only measure up to one amp. However, may 112-volt DC powered projects draw a lot more than that. If you have ever thought of purchasing a commercial shunt to solve the problem, your know just how expensive they can be. Commercial shunts, while very precise, frequently cost more than the projects they are measuring!..
The circuit's operating principle is that if you make a pulse width proportioal to inductance, and keep the pulse frequency and amplitude constant, and then pass the pulse through a low pass filter so that only the average voltage comes out, the resulting DC voltage is proportional to the inductance. Stated another way: Pulse width = Inductance X some constant. DC out = Pulse width X Pulse Ampltude X Freqency. Where DC out and Pulse Amplitude is in volts, and Pulse width.....
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 stage is not giving the gain you think it should. The circuit could hardly be simpler. The diode must be a high speed type, and germanium is ideal and cheap. Do not use an ordinary silicon diode - it won't work!.....
Many beginners trying out their skill with QRP TX, for the first time have to overcome many problems before they are able to come on the air. On usual complaint is that, every thing is working fine but the signal is not going out. Here is a simple set up which will enable them to measure the out put power of their transmitter. All that they require is a good multimeter which has a sensitivety of 20k ohms/4 Watts which is adequate for low power transmitters. The 8k resistor.....
Operational Amplifiers
Computer Systems
Oscilloscopes
Transmitters & Receivers
Sensors & Detectors
ANSI Standards
Low Frequency Amplifiers
Power Amplifiers
Number Systems
Regulated Power Supplies
Analogue Filters
Digital Gates
