Electrical circuit for pressure sensors: when is a sensor active, and when passive?

When using pressure sensors, the output signals 0 ? Refundable , 4 ? 20 mA and DC 0 ? 10 V are frequently chosen in order for the sensor signals to be evaluated and additional processed. For this, the signal output of the pressure sensor is usually connected to a corresponding input card in the PLC.
In Awesome can often be confusing, because the day-to-day usage of the terms ?active?, ?passive?, ?current source?, ?voltage source?, ?current sink? and ?load? tend to be wildly mixed together. Steamy processing always requires a voltage supply (an ?active part?) and a ?load?, such as a pressure sensor, which represents the ?passive part?. Sometimes the active portion of the interconnection is also referred to as an electrical source/voltage source and the passive part is known as a ?current sink?. To ensure that a power circuit can function, current must flow in a circuit ? even though an instrument is usually known as a load, the current isn’t consumed by it, rather it only flows from the current or voltage source through the load and back to the current source.
This works only when an ?energy gap? exists between current source and current sink, so the power source operates actively (= sending out current) and the current sink passively (= current flows through it) . Therefore, an interconnection of two current sources or two current sinks won’t operate normally. This example is complicated in day-to-day application:
When does a pressure sensor work passively (current sink) so when does it work actively (current source)?
How does the input card in my PLC operate?
Generally of thumb, you can keep in mind that 2-wire sensors usually work passively and therefore need an active PLC input card. It is difficult with 4-wire sensors, since, for instance, a 4-wire flow sensor includes 2 wires for a separate voltage supply and 2 wires for a dynamic or passive 0/4 ? 20 mA signal output. It is therefore imperative to check the datasheets for the sensor and PLC input card used.

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