2-12
MST-MHT SERIES 071320
2.9.1
LOAD CONNECTION WITH LOCAL ERROR SENSING
The most basic power supply/load interface is a 2-wire connection between the power supply
output terminals and the load. This connection method employs local error sensing which con-
sists of connecting the error sense leads (terminals S1+ and S2–) directly to the power supply
output (terminals O1+ and O2–). Its main virtue is simplicity: since voltage regulation is main-
tained at the power supply output, the regulation loop is essentially unaffected by the imped-
ances presented by the load interconnection scheme. The main disadvantage is that it cannot
compensate for losses introduced by the interconnection scheme and, therefore, regulation
degrades directly as a function of distance and load current. The main applications for this
method are for powering primarily resistive and relatively constant loads located close to the
power supply, or for loads requiring stabilized current exclusively. The load leads should be
tightly twisted to reduce pick-up.
2.9.2
LOAD CONNECTION WITH REMOTE ERROR SENSING
If the load is located at a distance from the power supply terminals, or if reactive and/or modu-
lated loads are present, remote error sensing should be used to minimize their effect on the volt-
age stabilization. A twisted shielded pair of wires from the sensing terminals directly to the load
will compensate for voltage drops in the load interconnection scheme (up to 0.5V maximum per
wire); the termination point of the error sensing leads should be at or as close as practical to the
load. Adapter Kit 219-0618 includes capacitive filtering, eliminating the typical requirement for
additional filtering capacitors. If adapter Kit 219-0618 is not used, it is recommended that some
amount of local decoupling capacitance be placed at the error sense termination point to mini-
mize the risk of unwanted pick-up affecting the remote error sense function. For very long power
module/load interconnecting cables and/or reactive loads, it may be necessary to add decou-
pling capacitors between the power and sense terminals at the power module side of the cable
to suppress oscillation due to cable inductance. A general recommendation is to install a net-
work of one (1) 10µF, 6.3V capacitor paralleled by one (1) 0.1µF ceramic capacitor across each
output sense pair (pins 6 to 5 and 3 to 2, respectively).
NOTE: As electrolytic capacitors are normally polarized make sure that the positive (+) terminal
of each one are respectively connected to the +V (pin 6) and -S (pin 2) pins.
TABLE 2-5. DC OUTPUT CONNECTOR/ADAPTER KIT TERMINAL DESIGNATIONS
MST-MHT SIGNAL
CONNECTOR TERMINAL
(See Figure 2-6)
Output Terminal 1 (+)
O1+
Output Terminal 2 (–)
O2-
Sense Terminal 1 (+)
S1+
Sense Terminal 2 (–)
S2-
Current Share Bus
CS
Module Chassis
GND
NOTE: The polarity for the terminals indicated above are for output enabled and polarity
not reversed (normal).
Summary of Contents for MST 100-2MHT
Page 2: ......
Page 8: ...iv MST SERIES 071320 FIGURE 1 1 MST POWER SUPPLY...
Page 13: ...MST MHT SERIES 071320 1 5 FIGURE 1 1 MST MHT POWER SUPPLY MECHANICAL OUTLINE DRAWING...
Page 16: ......
Page 30: ......
Page 39: ...MST MHT SERIES 071320 3 9 FIGURE 3 1 CALIBRATION TEST SET UP O2 S2 CS GND S1 O1...
