Mechanical electric shock switch value conversion circuit b

It is a conversion circuit for mechanical contact switching. The switch conversion circuit with its own power supply in the control system is generally used in situations where the switch is installed close to
the computer control device. The power supply is DC 24V or less. Commonly used circuits have two forms: series and parallel . For parallel circuits
, when the contacts are closed The output % is high level, and Vo is low level when the contact is open. A series circuit is just the opposite. The external power supply switch value conversion
switch is suitable for situations where the switch is installed far away from the control device. When a conversion circuit in the form of a DC power supply is used , the two transistors are protective
components, and the power factor should be considered in the selection.