O cenário
This circuit ensures two safety doors are closed before enabling a machine. Each door has a normally-closed switch that illuminates a 4N35 LED; the phototransistors are wired in AND configuration, so the output goes low only when both doors are closed.
O que há neste desenho
Entenda as decisões por trás dele.
01
Using NC switches for fail-safe operation
02
AND logic with series phototransistors
03
Optical isolation for noise immunity
Industrial machinery with multiple access doors requiring a safe start condition.