Hi all, I have a USB DAQ 6009 that I am going to use for some lab experiments. I have a few pressure sensors that need a 5V excitation voltage supplied to them. I know that USB is 5V, and that you can draw from this 5V on one of the terminals, but I was wondering if anybody can vouch for the stability of that 5V? For example, the max pressure I will read is somewhere like 0.4kPa on a 6kPa max sensor, and it outputs 0-4.5V. Just wondering if I am likely to encounter any major fluctuations at all, or will connecting it to the DAQ 5V terminal be fine?
On a similar note I also have a load cell and an amplifier, which is going to be weighing individual carbon fibres during an experiment, so that will have it's own power supply because the accuracy is paramount.
Unless you are using an industrial-grade, externally powered USB hub (like this one), I would not trust the USB power. I've seen too many motherboard USB hubs fail to supply enough current to handle anything more than one or two devices.