Bosch WT PSI 6 Series, Technical Information

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Suppression of RF noise
PSI 6XXX.190 W1
6-1
1070 080 086-101 (01.01) GB
6 Suppression of RF noise
Means of noise suppression are required to prevent radiation of radio frequency noise.
Such noise is caused by transients peaks, which are transmitted by the power supply line.
Noise should be neutralized at the source. If this is not practical, the noise suppression
devices must be placed as close as possible to the source.
All inductive devices such as valves, solenoids and other switching elements (or their
connecting wires), which are situated in the vicinity of the timer require noise suppres-
sion.
Because of inherent vibrations of the machine, the mounting of all noise suppression de-
vices must be resistant to fracture.
∼
GND
+
MP
Diode, suitable for small DC relays RC element for AC relays and AC
motors
DIODE RC ELEMENT
GND
+
DI-ZD attenuation element for large DC
contactors and defined drop-out times
RC element for spark quenching of in-
ductive loads
DIODE AND ZENER DIODE RC ELEMENT
Figure 8: Examples of noise suppression
Voltage Resistor Capacitor Diode
24 VDC
48 VDC
110 VAC
220 VAC
440 VAC
-
-
220 Ω /1 W
220 Ω /5 W
220 Ω /5 W
-
-
0.5 µ F 400/600 V
0.1 µ F 500 V
0.1 µ F 1000 V
1 N 5060/ZL 12
1 N 5060/ZL 22
This table serves only as an example. The actual component values depend on the spe-
cific load conditions.