Unformatted text preview: y way of display elements it should be noted that the switchon current of lamps with a cold spiral-wound filament is considerably higher than
the nominal current. It is therefore possible for the switch-on current to be
reduced as a result of preheating the spiral-wound filament by means of a bypass resistor which is connected in parallel to the proximity sensor.
• If a relay (a valve or an other high-inductance device) is to be actuated by
proximity sensors, they should be checked for built-in protection against voltage
peaks. If not, additional protection diode circuitry is to be provided. © Festo Didactic GmbH & Co. KG • FP 1110 153 10. Connection and circuit technology 10.6
Required current supply When switching on and off power supply units, care should be taken to ensure that
there are no voltage peaks which may jeopardise the function of the connected
proximity sensors. Power supply units with insufficient electronic control can create
voltage spikes during switch-on, which can be above t...
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- Spring '12
- pH, proximity sensors, Festo Didactic GmbH, Festo Didactic GmbH & Co