how voltage to current convertor transducer used for continuous voltage monitoring works? & what is its internal circuit?
A transducer is a device that converts one form of energy to another. Usually a transducer converts a signal in one form of energy to a signal in another.Transducers are often employed at the boundaries of automation, measurement, and control systems, where electrical signals are converted to and from other physical quantities (energy, force, torque, light, motion, position, etc.). The process of converting one form of energy to another is known as transduction.
Voltage-to-current converters feeding to grounded loads often find their way into industrial measurements and control applications. The conventional textbook circuit needs both positive and negative-supply rails.
ein - e1 = IL RS
Therefore, the load current is:
IL = ein/RS - e1/RS
The first term is proportional to the input voltage ein, and the second term is a constant. Here, e1 is derived from the negative power-supply rail through a potentiometer:
IL = ein/RS + (-e1)/RS
RS is selected so that the first term gives 16 mA for full-scale input voltage, and the potentiometer is adjusted so that the second term provides a constant 4 mA. In effect, the output ranges from 4 to 20 mA, corresponding with zero to full input voltage. But failure of the negative power supply causes erroneous output. Moreover, there may be equipment where the negative power supply is not available, requiring generation just for this application.
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