Puls ML15.121 Power Supply Guia De Especificação

Página de 23
 
 
ML15.121
 
 
MiniLine-2 
 
12V,
 
1.3A,
 
S
INGLE 
P
HASE 
I
NPUT
 
 
 
22.  A
PPLICATION 
N
OTES
 
22.1.  P
EAK 
C
URRENT 
C
APABILITY
 
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 (including the PowerBoost) The same situation applies, when starting a capacitive load. 
Branch circuits are often protected with circuit breakers or fuses. In case of a short or an overload in the branch circuit, 
the fuse needs a certain amount of over-current to trip or to blow. The peak current capability ensures the safe 
operation of subsequent circuit breakers. 
Assuming the input voltage is turned on before such an event, the built-in large sized output capacitors inside the 
power supply can deliver extra current. Discharging this capacitor causes a voltage dip on the output. The following 
two examples show typical voltage dips: 
 
 
Fig. 22-1   Peak loading with 2x the nominal 
current  for 50ms, typ. 
 
Fig. 22-2   Peak loading with 5x the nominal 
current  for 5ms, typ. 
 
10ms/DIV
Output
Voltage
Output
Current
12V
0A
2.6A
7.8V
 
 
1ms/DIV
Output
Voltage
Output
Current
12V
0A
6.5A
2V
 
 
Peak load 2.6A (resistive load) for 50ms 
Output voltage dips from 12V to 7.8V. 
 
Peak load 6.5A (resistive load) for 5ms 
Output voltage dips from 12V to 2V. 
 
22.2.  B
ACK
-
FEEDING 
L
OADS 
 
Loads such as decelerating motors and inductors can feed voltage back to the power supply. This feature is also called 
return voltage immunity or resistance against Back- E.M.F. (Electro Magnetic Force). 
The maximum allowed feed back voltage is 25Vdc. The absorbing energy can be calculated according to the built-in 
large sized output capacitor which is specified in chapter 6. 
This power supply is resistant and does not show malfunctioning when a load feeds back voltage to the power supply. 
It does not matter, whether the power supply is on or off. However, please note that the output voltage can dip to 
zero for approximately 200ms if the back-feed voltage is removed. 
 
Mar. 2013 / Rev. 2.1  DS-ML15.121-EN 
All parameters are specified at 12V, 1.3A, 230Vac input, 25°C ambient and after a 5 minutes run-in time unless otherwise noted. 
www.pulspower.com   Phone +49 89 9278 0    Germany 
18/23