Puls CP Series - Application Notes; Peak Current Capability

CP10.241-60
CP-Series
24V, 200W, DC/DC CONVERTER
P R E L I M I N A R Y
24. APPLICATION NOTES
24.1. PEAK CURRENT CAPABILITY
The unit can deliver peak currents (up to several milliseconds) which are higher than the specified short term currents.
This helps to start current demanding loads. Solenoids, contactors and pneumatic modules often have a steady state
coil and a pick-up coil. The inrush current demand of the pick-up coil is several times higher than the steady-state
current and usually exceeds the nominal output current. The same situation applies when starting a capacitive load.
The peak current capability also ensures the safe operation of subsequent circuit breakers of load circuits. The load
branches are often individually protected with circuit breakers or fuses. In case of a short or an overload in one branch
circuit, the fuse or circuit breaker need a certain amount of over-current to open in a timely manner. This avoids
voltage loss in adjacent circuits.
The extra current (peak current) is supplied by the power converter and the built-in large sized output capacitors of
the power supply. The capacitors get discharged during such an event, which causes a voltage dip on the output. The
following examples show typical voltage dips:
Fig. 24-1 Peak load with 2x the nominal
current for 50ms, typ.
Fig. 24-2 Peak load with 5x the nominal
current for 5ms, typ.
Output
Voltage
10ms/DIV
Output
Current
24V
0A
16.6A
15.5V
1ms/DIV
Output
Voltage
Output
Current
24V
0A
41.5A
15.5V
16.6A Peak load (resistive) for 50ms
Output voltage dips from 24V to 15.5V.
41.5A Peak load (resistive) for 5ms
Output voltage dips from 24V to 15.5V.
Fig. 24-3 25A Peak load, typ.
10ms/DIV
Output Voltage
Output Current
24V
0A
14ms
30A
10V
Please note: The DC-OK relay triggers when the voltage
dips more than 10% for longer than 1ms.
High Overload Current (typ. 25A for
12ms) enables easy fuse tripping
Peak current voltage dips Typically from 24V to 15.5V at 16.6A for 50ms, resistive load
Typically from 24V to 17V at 41.5A for 2ms, resistive load
Typically from 24V to 15.5V at 41.5A for 5ms, resistive load
May 2017 / Rev. 0.1 DS-QS10.241-60-EN preliminary
All parameters are typical values specified at 24V, 8.3A output, 110Vdc input, 25°C ambient and after a 5 minutes run-in time
unless otherwise noted.
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