Principle Of Operation; Functional Blocks; Preamplifier - Hoffer Flow Controls CAT1 User Manual

3. PRINCIPLE OF OPERATION

The CAT1 consists of two printed circuit boards and four main functional
blocks: the
Communications Interface.
FLOWMETER INPUT
4-20 mA
3-1

Functional Blocks

3-1-1

Preamplifier

The Preamplifier, located on PCA180, accepts the input from the
flowmeter. The Preamplifier applies amplification, low-pass filtering,
and wave-shaping to the input signal. The wave shaping function
converts the signal into a square-wave before sending it to the
Microcontroller.
Preamplifier,
PCA180
CONDITIONED SIGNAL
PREAMP
Principle of Operation
Microcontroller,
4-20 mA
Loop Driver,
PCA183
MICROCONTROLLER
COMMUNICATIONS
LOOP
INTERFACE
DRIVER
RS232
7
and
HP-310