3-wire proximity switch PNP, NPN's the difference?

1, PNP and NPN sensors generally have three pin-out, that is power line VCC, GND, OUT signal output line

1, NPN type

NPN is triggered when a signal, the signal output line OUT and GND connections, equivalent to the output OUT low.

2, PNP type

PNP is triggered when a signal, the signal output line OUT and VCC connections, equivalent to OUT output high power cord.

Multimeter can be used with power measurements, as follows: In the VCC, GND termination on the power supply, I plant close to three-wire switching power supply for the DC12-36V, with a piece of metal type things to put near the switch measured end, its indicator lights, DC voltage with the multimeter test files between OUT and GND voltage (red table pen then OUT, black table pen access GND), if there is voltage, indicating a high potential of the output OUT is a PNP type, if there is no voltage, indicating a low potential output OUT is a NPN type.

2., PNP and NPN type sensor

  PNP and NPN transistor sensor is actually using the saturation and cut-off, the output of two different states, belonging to switch-type sensors. But in either case the output signal is the opposite, namely, high and low.

  PNP output is low 0, NPN output is high one.

  PNP and NPN sensors (switch type) is divided into six categories:

  ○ 1, NPN-NO (normally open type)

  ○ 2, NPN-NC (normally closed type)

  ○ 3, NPN-NC NO (normally open, normally closed a total of type)

  ○ 4, PNP-NO (normally open type)

  ○ 5, PNP-NC (normally closed type)

  ○ 6, PNP-NC NO (normally open, normally closed a total of type)

  PNP and NPN sensors generally have three pin-out, that is power line VCC, 0V line, OUT signal output line.

  1, NPN type

  NPN is triggered when a signal, the signal output line OUT and VCC power line connections, the equivalent output of high power lines.

  NPN-NO type, in the absence of the signal is triggered, the output line is left vacant, namely, VCC power line and the OUT-line disconnect; when the signal triggered, OUT and VCC power line voltage is the same, both connected to the output of high power Ping VCC.

  NPN-NC type, in the absence of the signal triggered, OUT and VCC power line voltage is the same, the output high VCC; when the signal is triggered, the output line is left vacant, namely, VCC power line and out line disconnected.

  NPN-NC NO type, is actually more an output line OUT, the user can choose.

  2, PNP type

  PNP refers to the signal is triggered, the signal output OUT and 0V line connection, equivalent to the output low 0V.

  PNP-NO type, in the absence of the signal is triggered, the output line is vacant, is the 0V line and the OUT-line disconnected. When a signal is triggered, OUT line and 0V lines connected to the same voltage, output low OV.

  PNP-NC type, with the PNP-NO-based characteristics of the opposite.

  PNP-NC NO type, and the NPN-NC NO type is similar to an extra output line OUT, that is, two signal inversion of the output line.

  commonly used is the PNP type, that is, high active state. NPN seldom used.