I'm really lost and researching for two days now. I want to read a 10V Tachometer which also can be up to 28V. Which Optocoupler or transistor can I use in order to make it work with a Digitial IO on an Arduino Uno REV3.
The fan has a 10Vdc (output) pulse, but also it must be able to read a 28Vdc (output) pulse. Is there a way to read both voltages on the same Digital Input?
Your setup has just one input pin & Gnd, that will see a 10V signal, or up to a 28V signal, yes? And not both at once?
A simple transistor as buffer will do that.
Hi,
The opto-coupler is a valid option but you would have to check if the TACHO output is a pulse or to get a pulse you need to connect the output to Vcc via a resistor.
(NPN Open Circuit Collector output)
The other fan has a plain and simple 24VDC output. Is there a way to connect the one or the other voltage on the same Digital Input? (Arduino Uno PIN3)
Just so you can use interrupts ?
Well yes, but i guess you'd want to switch between inputs ? You could use a logic-gate (CMOS or 7400 series TTL) to switch between inputs.