1-12
BHK-1/2-MG (OPR) 030916
g.
Overload of the main or auxiliary power transformer.
If input current of the main trans-
former exceeds 1.1A a-c @ 115V a-c or 0.6A a-c @ 230V a-c, the input POWER circuit
breaker is tripped to OFF, the pass element is cut off, the output capacitor is discharged, and
a flag is sent to the Status Port connector. The reaction time is inversely proportional to the
input overcurrent: from a minimum of 10ms for 10 times nominal current, to a maximum of
100 seconds for 25% above nominal current.
If input current of the auxiliary power transformer exceeds a predetermined value, the PTC
(Positive Thermal Coefficient) thermistor (in series with the primaries of the auxiliary trans-
formers) resistance will increase, thus reducing the voltage across the primary of the corre-
sponding transformer. If this occurs, the pass element will be cut off. In some circumstances,
depending upon which transformer is involved and whether an overcurrent condition is
detected during or after power-up, the input circuit breaker may trip OFF.
h.
Current Limit.
The current through the pass and sink elements is monitored. If this current is
1.5 times larger than the nominal value for more than 20ms, the pass element is cut off, the
output capacitor is discharged, and the POWER circuit breaker is tripped to OFF. A flag is
sent to the host computer via the Status and Remote On/Off Port.
1.4.10
ANALOG READBACK AND FLAG SIGNALS AVAILABLE FOR CUSTOMER USE
Some internal signals produced by the unit are available at connector A2J5 for either monitoring
or testing purposes. Refer to Table 1-3 for a description of available signals.
1.4.11
EXTERNAL TRIGGER PORT
The External Trigger Port provides two functions: a shutdown input can be used to immediately
shut down the power supply output (see PAR. 3.2.7.3) and a trigger input can be used to restore
the output to previously defined settings (see PAR. 3.3.4).
TABLE 1-3. CONNECTOR A2J5 SIGNAL DESCRIPTIONS
SIGNAL
PIN. NO.
VALUE
TYPE
Step Down Flag
2
< –11V for steady or step-up output
> +11V for step-down output, or when pro-
tection circuit has functioned.
Output of open loop Op Amp
(A2U2C) through 1K resistance.*
V-C Mode Flag
3
< –11V for CV (Constant Voltage) mode
> +11V for CC (Constant Current) mode
Output of open loop Op Amp
(A2U2A) through 1K resistance.*
Source-sink Flag
4
–11V for sink
> +11V for source
Output of open loop Op Amp (A2U9)
through 1K resistance.*
Power GND
5
N/A
Recommended to be used as Return
for signal at pin 2.
Current Monitor
(not calibrated)
6
0V ± 10mV (for IO = 0mA) to
+10V ± 0.12V (for IO = Full Scale)
Output of closed loop Op Amp
(A2U14B) *
Signal GND
7
N/A
Recommended to be used as Return
for signals at pins 6 and 8.
Voltage Monitor
(not calibrated)
8
0V ± 10mV (for EO = 0V) to
+10V ± 0.25V (for EO = Full Scale)
Output of closed loop Op Amp
(A2U1B) *
* Recommended load equal to or greater than 10K ohms.
Summary of Contents for BHK-MG Series
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Page 18: ...xii BHK MG030916 FIGURE 1 1 BHK MG 40W SERIES PROGRAMMABLE POWER SUPPLY...
Page 26: ...1 8 BHK 1 2 MG OPR 030916 FIGURE 1 3 RA 24 RACK ADAPTER WITH TWO 1 2 RACK BHK MG 40W UNITS...
Page 35: ...BHK 1 2 MG SERIES 030916 2 3 FIGURE 2 2 BHK MG SERIES REAR PANEL CONTROLS AND CONNECTIONS...
Page 100: ...3 54 BHK 1 2 MG 030916 FIGURE 3 20 SERIES AUTOMATIC CONFIGURATION...
Page 113: ...BHK 1 2 MG 030916 3 67 FIGURE 3 25 PARALLEL MASTER SLAVE CURRENT MODE CONFIGURATION...
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