3S TE100 Instrukcja obsługi - Strona 6

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Principle of Operation

＜ Transducer Operation Schematic ＞

As shown in the above schematic, the operation of the I/P Converter is controlled by applying a

4 to 20mA DC signal to the input which causes the internal circuit to generate a voltage. A drive

current is also supplied to the torque motor which represents the circuit load to operate the

overall system. If the level of the input signal increases, the current to the torque motor [1]

increases and the flapper [2] moves so as to cover the nozzle [3] and raise the pressure in the

pilot relay (pneumatic valve) nozzle back-pressure chamber [4]. The increased nozzle

back-pressure causes a displacement in the diaphragm assembly [5] in the pilot relay, opening

the port's [6] inlet valve seat [7]. This increases the output air pressure from the pilot relay. The

output air pressure is also applied to the pressure sensor [8] and converted into an electrical

signal proportional to the pressure. This electrical signal is then returned to the control circuit

where it is used as a feedback signal. The control circuit compares the sensor signal against the

input signal to control the output air pressure to match the input signal.

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