Theory Of Operation; Circuit Theory Of Operation; Functional Block Diagram Description; Power Supplies - ConMed Sabre 2400 Operators & Service Manual

3.1 CIRCUIT THEORY OF OPERATION

This section contains the theory of operation for
the Sabre 2400 circuitry. The functional block
diagram and schematics are located in Section
4.0. These schematics are folded such that they
may be pulled out for viewing while reading the
appropriate section.

3.1.1 Functional Block Diagram Description

The Functional Block Diagram appears in Figure
4.1. This diagram illustrates the functional blocks
and their physical location by assembly number.
Each block defines a major function (as noted
inside the block), the reference designator(s) of
the primary components(s), and the schematic
number where the block is detailed.
The relationships among each block are described
by the signals that interconnect them. Narrow
lines represent individual signals and are marked
with the same signal mnemonics used in the sche-
matics. Broad lines denote busses, or groups of
signals which together serve a common function.
To avoid clutter, busses are not necessarily marked
with signal mnemonics.
Arrowheads describe the direction of signal flow.
In the case of bidirectional signals, there are
arrowheads on each end of the signal lines.

3.1.2 Power Supplies

Refer to Schematic 4.6. The mains power cord
terminates to a grounding lug on the base, and
the two-pole circuit breaker, CB1, mounted on
the output panel. CB1 serves both as a lighted
power switch and to protect the unit from over-
loads. On overload, this device automatically
switches its handle to the OFF position.
R

Theory of Operation

Section 3.0
The switched AC is wired to TB1 for connection
to the primary windings of power transformer
A5T1. Strapping options on TB1 set the unit for
a given mains voltage range. Schematic 4.6 indi-
cates the strapping options for the various mains
voltages.
The high power secondary of A5T1 (wires are
marked 4 and 5) is wired to full wave rectifier
A5BR1, and the DC output of the rectifier is
connected to the Power Board through J3 on the
Power Board. A1C1 and C2 are filter capacitors
for the resulting dc voltage RFSUP . The LED,
A1DS1, is an indicator that high voltage is still
present, even when the power switch is off. R64
acts as a bleeder to discharge C1 and C2.
The low power secondary of A5T1 (wires 1, 2,
and 3) is wired directly to the same connector J3.
A5BR1 acts as a conventional full-wave bridge
rectifier for supplying +22UNREG, while simul-
taneously acting as a negative-leg full-wave cen-
ter-tap rectifier in providing +11UNREG. A1C7
and C10 are the filter caps for the low voltage
supplies.
+22UNREG is the source for the +12V
regulator on A2, the transistor drive (Vbase),
and the relay power supply voltage RLYSUP .
+11UNREG supplies the raw voltage for the
+5V regulator, also on A2.
3-1