My idea is to make a pressure sensetive switch, that can be used universally, kind of like the pressure sensetive buttons on a ps2 controller. Does anyone have any ideas? Maby a linear Pot with a strong spring under it, allowing less resistance the farther you push and thus the more pressure you put on it.
Y
Yevgenip
- Jan 1, 1970
- 0
It depends on what exactly you want to use it for.
The simplest way would be to make the switch change capacitance when pressed. You achieve this by putting a metal plate on the base of the switch and another on the moving part. when you press the switch, it will change capacitance (I don't remember: Increase/decrease).
Am I wrong?
If you want to use high pressures, try making it hydro.
The simplest way would be to make the switch change capacitance when pressed. You achieve this by putting a metal plate on the base of the switch and another on the moving part. when you press the switch, it will change capacitance (I don't remember: Increase/decrease).
Am I wrong?
If you want to use high pressures, try making it hydro.
Is this similar to the effect you get when your short out a switch with your finger, and the harder you press, the less resistance your skin has? I don't plan on putting on any more pressure than what can be exherted by pressing it your finger.
Y
Yevgenip
- Jan 1, 1970
- 0
I think my idea is better because you CAN make a FET pressure switch that is activated by the least resistance of your finger, but then you will not have much range of sesitivity.
If you still want the finger thing, I'll post a very basic schematic in a while.
If you still want the finger thing, I'll post a very basic schematic in a while.
surajbarkale
- Aug 5, 2004
- 256
- Joined
- Aug 5, 2004
- Messages
- 256
Sandwhich a rubber pad between two metal plates. This will form a variable pressure sensitive capacitor. Much reliable than human finger 
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Hi tweak232,
this circuit that I posted is still work in progress, D1 is not needed. You could use a hall affects sensor, but as you can see it requires a few components, and is probably a bit of an overkill for what you want. But it is very flexible, and you can make it work like the PS/2 controller, and the amount of pressure required to push the button in, is only limited to the spring required to return the button.
View attachment 36297
this circuit that I posted is still work in progress, D1 is not needed. You could use a hall affects sensor, but as you can see it requires a few components, and is probably a bit of an overkill for what you want. But it is very flexible, and you can make it work like the PS/2 controller, and the amount of pressure required to push the button in, is only limited to the spring required to return the button.
View attachment 36297
Y
Yevgenip
- Jan 1, 1970
- 0
I got the formula for a capacitor made out of two metal plates seperated by an isolator:
C=E*A/d
When:
C = The capacitance in [Farads].
E = The material constant in [Farads/Meter].
A = The material area in [Meter^2].
d = The distance between the plates in [Meter].
About the circuit posted: Where does the switch go?
C=E*A/d
When:
C = The capacitance in [Farads].
E = The material constant in [Farads/Meter].
A = The material area in [Meter^2].
d = The distance between the plates in [Meter].
About the circuit posted: Where does the switch go?
U1 is the hall affects sensor, which is placed beneath the button. Then you place a magnet within the underside of the button, the voltage rise and fall from pin 1 of U2, will correspond to the magnet travel towards an away from the hall affects sensor.
I hope this has been helpful
.
Y
Yevgenip
- Jan 1, 1970
- 0
Moist is no problem with the right casing. ;D
What is Hall Effect? ???
What is Hall Effect? ???
Y
Yevgenip
- Jan 1, 1970
- 0
Thanks Ante!!! and Dazza!!! That cleared a few things out!
Yes, a hall efect will probebly be better.
Yes, a hall efect will probebly be better.
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