Description
:
Capacitive proximity sensor is non-contact sensing solution to metallic
as well as non-metallic objects. With adjustable sensitivity almost
any medium can be detected with desired reliability.
Design
and Principle..
The primary functional element of Capacitive proximity switch is
high frequency oscillator with floating electrode in the transistor
base circuit. In non-activated state, noise field exists in region
of base electrode which represents active area of proximity switch.
When medium appears in active area, oscillations begin. The switching
stage rectifies and switches high frequency oscillations, resulting
DC signal triggers output stage. Switching stage includes signal
feedback system, level of which can be adjusted by potentiometer,
thus providing presentable response sensitivity of switch. |
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