| Electronics > Projects, Designs, and Technical Stuff |
| Liquid Level Circuit Design |
| << < (4/4) |
| sirklezero:
I really appreciate the feedback of this group so far, thanks everyone! It seems like, other than adding some caps at the inputs of the NOR gates (which I'm still a little fuzzy on), it seems that for the most part this should work out really well for me. I think I might poke around with some of the other ideas for water level detection, this is a learning project after-all, so the experience will be well worth it regardless of the end outcome. Can someone help me understand how the caps benefit the circuit in this case? Is it a protection for the inputs of the NOR gates from something going wrong on the sensor side of things? |
| IanB:
--- Quote from: sirklezero on December 11, 2018, 04:10:22 am ---...other than adding some caps at the inputs of the NOR gates (which I'm still a little fuzzy on)... Can someone help me understand how the caps benefit the circuit in this case? Is it a protection for the inputs of the NOR gates from something going wrong on the sensor side of things? --- End quote --- The caps don't go on the inputs, they go on the power supply pins. Essentially place the capacitor between the power (+) and power (-) pins of the IC, as close to the IC as possible. These are "bypass" capacitors, they help to prevent high frequency glitches in the supply messing up the operation of the chip. Such glitches can be caused when the logic gates switch state (they draw a pulse of current when they switch). |
| raptor1956:
--- Quote from: t1d on December 10, 2018, 10:39:55 am ---I have always thought "capacitive water level sensors" to be interesting and doable. I think that they can be as simple as one piece of metal pipe inserted into another? https://www.google.com/search?q=capacitive+water+level+sensor+circuit&client=firefox-b-1&tbm=isch&tbo=u&source=univ&sa=X&ved=2ahUKEwiMie64h5XfAhUNXa0KHX1xA74QsAR6BAgEEAE&biw=1280&bih=667 https://www.instructables.com/id/Capacitive-Fluid-Level-Sensor/ --- End quote --- Fuel quantity sensors on aircraft use capacitance sensors to measure fuel level. The probe has contoured plates so that variation in tank geometry is figured in. In addition, a compensator capacitor is used to compensate for fuel density as the temperature changes. Ultimately this arrangement provides a fuel reading by mass that is more accurate than by level alone. Brian |
| Navigation |
| Message Index |
| Previous page |