PRESSURE SENSORS & LOAD CELLS
| WHAT CAN YOU SENSE? |
Pressure, bend, strain, generally steady state. |
| WHO MAKES THEM? |
CARBON MICS: |
| WHERE CAN YOU BUY THEM? | |
| HOW DO THEY WORK? | These
devices work on the principle of dynamic resistance. Two metal plates with
carbon granules in between work to do this or sometimes just a nichrome
or platinum wire (strain gauges) are used as a source of dynamic resistance.
As pressure is applied, the carbon molecules rub against eachother (think
Velcro like) (or with the case of the carbon mic, the plates vibrate), and
the resistance changes.
They generally respond to steady
state force (for example if you sit on something). |
| EXAMPLE CIRCUITS: | |
| PITFALLS & SOLUTIONS: |
FSRs don't like shear force. Silicon rubber does not have a broad range of resistance. Bend Sensors can't tell you where the bend it, only how something bends. Strain gauges can only provide
resistence of 50 - 100 ohms |
| OTHER WAYS TO SENSE THIS: | Pressure through displacement: Capacitive, sonar, inductive, optical sensing mechanisms can all detect displacement. |
| ETC |