Manual

1-12 BHK-1/2-MG (OPR) 121313
1.4.12 CURRENT SINK CAPABILITY
BHK-MG 40W Series power supplies are able to sink up to 5% of the nominal current when in
voltage mode and greater than 75% of the unit's maximum rated current when in current mode.
The fixed current mode sink value is model dependent and has a tolerance of 10%. When the
BHK-MG 40W is in sink mode, the unit displays the word "Sink" and the sink current value (neg-
ative) on the front panel display. This capability is useful in applications such as capacitor test-
ing, where the sink capability allows the rapid discharge of the device under test, permitting
subsequent tests to be started earlier, thus increasing the throughput of the testing process.
The sink current in current mode is quite stable, allowing this feature to be used with the dis-
charging process to determine the value of a capacitor under test by measuring the discharge
time, using the formula C = T x I / V (the charge time, which is more accurate, can also be used
in the formula), where
T = discharge or charge time
V = change in voltage from fully charged to fully discharged, or vice versa.
I = discharging or charging current (BHK-MG charging current has a tolerance of
0.05% of nominal value, discharge current has a tolerance of 10% of nominal value)
The value of the capacitor under test can be calculated directly by measuring T and either using
the above formula and the appropriate tolerance for I, or by comparing T to that of a known
capacitor value.
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 I
O
= 0mA) to
+10V ± 0.12V (for I
O
= 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 E
O
= 0V) to
+10V ± 0.25V (for E
O
= Full Scale)
Output of closed loop Op Amp
(A2U1B) *
* Recommended load equal to or greater than 10K ohms.