Rectifier Type Voltmeter
In general, a rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The reverse operation is performed by the inverter. These voltmeters are used to measure either AC or DC.
Measurement of AC voltage requires a rectifier in the circuit so that the coil deflects in only one direction. A PMMC meter that detects pulsing DC voltage and rectified voltage that is linked across the bridge rectifier must be connected for DC measurement.
This method is very attractive since PM MC instruments have a higher sensitivity than the electrodynamometer or the moving iron instruments. The arrangement which employs a full wave.
Other types of voltmeters are:
Voltmeter – Symbol of Voltmeter
In circuit diagrams, a voltmeter is represented by the letter V in a circle, with two emerging lines representing the two points of measurement.
Voltmeter and Hydraulic Analogy
The hydraulic analogy, or the electric-fluid analogy, is a widely used analogy between hydraulics and electricity, which is a useful tool for teaching and for those who are struggling to understand how circuits work. it can also be applied to heat transfer problems.
Since electric current is invisible and the processes in play in electronics are often difficult to demonstrate, the various electronic components are represented by hydraulic equivalents. The relationship between voltage and current is defined (in ohmic devices like resistors) by Ohm’s law. Ohm’s Law is analogous to the Hagen–Poiseuille equation, as both are linear models relating flux and potential in their respective systems.
Electricity (as well as heat) was originally understood to be a kind of fluid, and the names of certain electric quantities (such as current) are derived from hydraulic equivalents.
Voltage is like the pressure difference that pushes water through the hose. It is measured in volts (V). This model assumes that the water is flowing horizontally so that the force of gravity can be ignored. So that voltmeter is equivalent to pressure difference measurement.