Why open collector

Limit input and output voltages to the maximum specified on your Phidget's specification table, and always observe correct polarity. Views View View source History. Tools What links here Printable version Page information. Phidget SBC. Visual Basic. Objective C. Phidgets Support and Documentation. Support Phidgets. Getting Started. Go To Phidget These outputs have a simple design but play an important role in applications spanning multiple industries.

Open collectors are outputs you can find on different electronics and most integrated circuit IC boards. These work with DC power and behave a lot like power switches or Solid State Relays SSRs , allowing you to toggle the input signal to turn different circuitry on or off. An open collector is either wholly off or fully on — they do not also amplify or attenuate. An open collector diode is sometimes included in the series to protect against unexpected voltage shifts.

In addition to the collector, an Open-Collector Output also has a base and an emitter. These transistors have a passive open collector output that either connects to an electrical ground or generates a floating voltage.

The component takes its input signal from the IC board and activates. When the PNP is active high , it will overpower the pull-down and hold the digital input high. Note that if the PNP high voltage is greater than 5 volts, Rseries is needed to protect the digital input as discussed earlier. In this case Rseries combines with Rpulldown to create a voltage divider and also the internal k pull-up to 3.

We recommend always using a 4. Various mention is made above to protecting from voltages greater than 5 volts. The actual limits can be found in Appendix A of each device's datasheet.

Note that an individual ground connection to the LabJack is often not needed for every signal. Any signals powered by the same external supply, or otherwise referred to the same external ground, should share a single ground connection to the LabJack whenever possible. Every LabJack is backed by our free Legendary Support, for life.

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