Filter
Top Products
Bosch Security Systems | 2011-02
Praesideo 3.5 | Installation and User Instructions | 4 | Amplifiers en | 155
8.8.12 Derating
The graph shows the available continuous power used
for emergency tones, speech, etc. as function of the
ambient temperature.
If the amplifier is loaded with loudspeakers up to its
rated output power (see section 8.8.12), you can still
play music and speech for an indefinite long period of
time at an ambient temperature of 55 °C, because of the
crest factor (or peak-to-average ratio) of the audio
signals. The crest factor of music and speech is typically
6 to 8 dB, which makes the required continuous power
25% or less of the rated output power. Alarm tones are
set to -3 dB maximum by Praesideo, resulting in a
required continuous power of 50% of the rated output
power. This can be delivered for at least 30 minutes at
55 °C ambient or continuously at 30 °C ambient.
8.8.13 Control inputs
figure 8.20: Output power derating
55
25 30 35 40 45 50 55 60
50
45
40
35
30
25
20
Continuous Output Power
(% of Rated Output Power)
T (°C)
Connector (rear side):
16 pole header (type Phoenix MC1,5/16-G-3,81) for
removable screw connector (MC1,5/16-SWT-3,81)
Total cable resistance:
< 1 kohm (with line supervision)
< 5 kohm (without line supervision)
Resistance detection (supervision enabled):
Cable short circuit
< 2.5 kohm
Contact closed
7. 5 k o h m to12 kohm
Contact open
17. 5 k o h m to 22 kohm
Cable broken
> 27 kohm
Resistance detection (supervision disabled):
Contact closed
< 12 kohm
Contact open
> 17.5 ko h m
External contacts:
Voltage-free closing or breaking contacts (relay
contacts, mechanical switches, mercury contacts
etc.)