Seeking help with pulse signal issues of turbine flowmeters
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I suspect I got confused after looking at the information from various manufacturers. Flowmeters that generate such pulse signals, as well as some speed sensors, all output pulses. For example, take flow meters – those powered by 24V output such a frequency, with the high level being above 20V and the low level below 1V; this is easier for me to understand, and I can connect them to a digital display to show the values. As for speed sensors, they are also powered by 24V, with the high level at 0.7V and the low level at 0V; these can be connected to the same digital display as well. There are also some sensors whose high levels are 5V or 12V. But I see that, as the receiver, the signal collector doesn’t seem to have any requirements regarding this level either; does the frequency signal collector really not have any requirements concerning the level? For example, for a signal collector that normally accepts 5V high-level signals, can I connect a sensor that outputs a high level of 20V to it? I’m not in the electronics field; have I misunderstood some concepts? Please give me some advice
Check the receiver’s manual to find out what the acceptable voltage range is; otherwise, connecting a high voltage to a low-voltage terminal may not result in signal reception, while connecting a low voltage to a high-voltage terminal could damage the receiver.
Measurement instruments output and receive pulse signals, and there are basically two parameters that need to be considered: one is the voltage range of the pulses, which relates to the quality of the pulse signals; the other is the frequency range of the pulses, which relates to their quantity. The signal that can be received at the receiving end must fall within these specified ranges.
If the sensor’s output is at the collector terminal, then with a supply voltage of 24V, can signal levels of any value be achieved by using pull-down resistors?