Capacitive Liquid Level Sensing (3): Measuring Capacity (2) скачать в хорошем качестве

Capacitive Liquid Level Sensing (3): Measuring Capacity (2)

Third part, about a third principle method of measuring capacity … ↓↓↓ Complete description, time index and links below ↓↓↓ In the second video we’ve covered two principle ways of measuring capacity (link below). Turns out that the second principle we’ve had a look at (RC charge curve) lends itself to a third method: RC oscillators. So let’s have a look at those. We start out with a simple RC oscillator around an inverter with a Schmitt-trigger input and the easy math governing it. But soon we’ll discover that when working with pF and MOhm things are complicated and parasitic effects get very visible. 00:00 Intro – a third way to measure capacity 01:01 RC oscillator – with 74HCT14 Schmitt-trigger inverter 07:08 The math – frequency inverse proportional to capacity 10:34 Duty cycle – not that it matters, but why isn’t it 50% 14:04 Parasitic capacitances – messing up the nice math 24:21 Alternative chips – LMC555 (CMOS) and comparators 26:09 Frequency & EMI – keeping it low is key 27:52 Wrap-up – next time we’ll actually use an MCU, bye Tutorials    • Tutorials   Capacitive Liquid Level Sensing (1): Sensor Basics    • Capacitive Liquid Level Sensing (1): ...   Capacitive Liquid Level Sensing (2): Measuring Capacity (1)    • Capacitive Liquid Level Sensing (2): ...   #liquid #sensor #capacitance #capacity #capacitor #tutorials #tutorial #how-to #robertssmorgasbord