QS20.241 datasheet(21/26 Pages) PULS

21 / 26 page

QS20.241, QS20.241-A1, QS20.241-C1

Q-Series

24V, 20A, SINGLE PHASE INPUT

22. APPLICATION NOTES

22.1. REPETITIVE PULSE LOADING

Typically, a load current is not constant and varies over time. This power supply is designed to support loads with a

higher short-term power demand (=BonusPower®). The short-term duration is hardware controlled by an output

power manager and is available on a repeated basis. If the BonusPower® load lasts longer than the hardware

controller allows it, the output voltage will dip and the next BonusPower® is available after the BonusPower® recovery

time (see chapter 6) has elapsed.

To avoid this, the following rules must be met:

The power demand of the pulse must be below 150% of the nominal output power.

The duration of the pulse power must be shorter than the allowed BonusPower® time. (see output section)

The average (R.M.S.) output current must be below the specified continuous output current.

If the R.M.S. current is higher, the unit will respond with a thermal shut-down after a period of time. Use the

maximum duty cycle curve (Fig. 22-2) to check if the average output current is below the nominal current.

Fig. 22-1 Repetitive pulse loads, definitions

Fig. 22-2 Max. duty cycle curve

100%

PEAK

max.

150%

100

0.2

0.4

0.6

0.8

1.0

DutyCycle

110

120

130

140

PEAK

0 = 10%

0 = 50%

0 = 75%

0 = 100%

Base load (W)

PPEAK Pulse load (above 100%)

Duration between pulses (s)

TPEAK Pulse duration (s)

DutyCycle

0 =

Tpeak - (DutyCycle x Tpeak)

Tpeak + T0

Tpeak

DutyCycle =

Example:

A load is powered continuously with 240W (= 50% of the rated output load). From time to time a peak

power of 720W (= 150% of the rated output load) is needed for 1 second.

The question is: How often can this pulse be supplied without overloading the power supply?

- Make a vertical line at PPEAK = 150% and a horizontal line where the vertical line crosses the P0 = 50%

curve. Read the max. duty cycle from the duty cycle-axis (= 0.37)

- Calculate the required pause (base load) length T0:

21/26

- Result: The required pause length = 1.7s

- Max. repetition rate = pulse +pause length = 2.7s

More examples for pulse load compatibility:

PPEAK

TPEAK

PPEAK

TPEAK

720W

480W

>25s

720W

240W

0.1s

>0.16s

720W

>1.3s

720W

240W

>1.6s

600W

240W

> 0.75s

720W

240W

>4.9s

DutyCycle

Tpeak - (DutyCycle x Tpeak)

0.37

1s - (0.37 x 1s)

== 1.7s

Oct. 2013 / Rev. 2.2 DS-QS20.241-EN

All parameters are specified at 24V, 20A, 230Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

www.pulspower.com Phone +49 89 9278 0

Germany

QS20.241 Datasheet(PDF) 21 Page - PULS GmbH

QS20.241 Datasheet(HTML) 21 Page - PULS GmbH

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

Datasheet Download

Link URL