Teledyne 9700 - Flue gas analysis system - Manual (Page 12)

8
General Information Model 9700
TELEDYNE BROWN ENGINEERING
Analytical Instruments
• E-to-I Converter
A voltage (E) to current (I) conversion of the output signal
generated by the analyzer is available. This conversion allows I
(current) to P (pneumatic) devices, as well as low-impedance
current-operated indicating and/or recording and controlling
instruments to be directly driven without the need of accessory
equipment.
One of the following three ranges of current output is available:
• 1 to 5 mA dc,
• 4 to 20 mA dc
• 10 to 50 mA dc.
The designation 326B-I signifies an analyzer equipped with an E to
I converter.
• Differential Power Supply
Both integral alarm and E-to-I converter options are plug-in
printed circuit boards for quick replacing. When either or both
of the options are employed in an instrument, a highly regulated
differential power supply (also a plug-in printed circuit board)
is included to supply the positive and negative voltage required
by the semiconductor circuitry.
The basic Model 326B employs a simple unregulated power
supply. The rectifying diodes and filtering capacitors are
located on the same circuit board as the detection and amplifier
circuitry. The alarm comparator and converter circuits,
however, require that the supply voltage remain at a constant
level to all circuitry in the interest of accuracy. When options
are employed, the unregulated power supply components are
deleted from the amplifier board, and the amplifier, as well as
the option circuit, are fed from the regulated differential power
supply.