Number of controls are required to be provided on a panel of CRO to facilitate its proper functioning. Intensity control is provided for adjustment of brightness of the spot on the screen. It is accomplished by varying the voltage between the first and second anodes. The horizontal and vertical position controls are provided for moving […]
Cathode ray tube essentially consists of an electron gun for producing a stream of electrons, focusing and accelerating anodes for producing a narrow and sharply focused electron beam, horizontal and vertical deflection plates for controlling the beam path and an evacuated glass envelope with phosphorescent screen giving bright spot when struck by a high velocity
A CRO (Cathode Ray Oscilloscope) is an electronic instrument used for studying various electrical & electronic parameters and behaviors. CRO is basically an XY (2 dimensional) plotter which can plot an input signal vs another signal or an input signal vs time. A cathode ray oscilloscope is used to study waveforms, transients, time based or
Q-Meter We know that every inductor coil has a certain amount of resistance and the coil should have lowest possible resistance. The ratio of the inductive reactance to the effective resistance of the coil is called the quality factor  or Q-factor of the coil. So Q = XL / R = ωL / R A
Electronic Multimeters It is one of the most versatile general purpose instruments capable of measuring dc and ac voltages as well as current and resistances. The solid-state electronic multimeter (or VOM) generally consists of the following elements. A balanced bridge dc amÂplifier and a PMMC meter. An attenuator in input stage to select the proper
Electronic Galvanometers A vacuum tube or transistor amplifier, followed by a milli-ammeter may be employed as a detector. Some of such devices have arbitrary scale values, sometimes with variable gain, and are designed simply as balance indicators. The sensitivity may be of the order of a microvolt per scale division or better, and the input impedance is
Balanced Bridge Voltmeters Such voltmeters can be used for measurement of both dc and ac voltages and are very popular. These voltmeters are available in both versions, vacuum tube type and transistorized type and are described below: (a) Balanced Bridge Triode VTVM. The circuit diagram of a balanced bridge triode VTVM is shown in figure.
True RMS Reading Voltmeter RMS value of the sinusoidal waveform is measÂured by the average reading voltmeter of which scale is calibrated in terms of rms value. This method is quite simple and less expensive. But sometimes rms value of the non-sinusoidal waveform is required to be measured. For such a measurement a true rms
In electronic ac voltmeÂters input signal is firstly rectified and then supÂplied to the dc amplifier, as shown in figure. Sometimes signal is firstly amplified by ac amplifier and then rectiÂfied before supplying it to dc meter, as shown in figure. In the former case the advantage is of economical amplifiers and the arrangement is usually used
DC Voltmeter Block Diagram DC voltmeter mainly consists of a dc ampliÂfier apart from the attenuator, as shown in figure. DC voltmeters can further be divided into two categories. 1. Direct Coupled Amplifier DC Voltmeter This type of voltmeter is very common because of its low cost. This instrument can be used only to
In all electronic voltmeter circuits the principle involved is that an indication on a permanent magnet moving coil instrument (normally abbreviated as PMMC or D’Arsonval movement) proportional to the input voltage is obtained by means of amplification in one or more stages with a high input impedance. Although electronic instruments are usually more costlier than
