Hello.I need something very simple, without any mems/gyro/etc. to sense the position of device. The circuit should be triggered when device turned over. Do they exist?
It used to be a bead of mercury rolling from one end of a tube to the other, but that is out now. There are still tilt sensors available that consist of a tube sealed with liquid inside, and electrodes placed to detect the position of a bubble of inert gas.
The one Andrew mentioned, the Memsic sensor from Parallax, is very rugged--no moving parts. It detects the distribution of a bubble of warm gas inside a tiny chamber.
>my 180 degree requirement, I can install two of these 45 degree ICs in angle
Does your product have a mcu?, more info could help.
Freescale's IC does do negative G to detect upside down, but the Tilt Detection Output's are absolute values, eg -1 = 1
The tilt sensor that I mentioned can easily be used without an MCU. You could use the outputs to drive logic gates to perform the function of enabling the device when turned over. I have one specifically for that reason. I am going to use it to drive Pololu's pushbutton power switch.
If you mount the mechanical e-switch above upside down, and you OR the two outputs.
I think you should only get a 0 if the item is upside down (135deg to 225deg)
tonyp12, thanks for the follow up. I figured there was a simple way with a single logic gate (and, nand, or, nor), but my real life application of Boolean is rusty.
Comments
http://www.mouser.com/ProductDetail/Freescale-Semiconductor/MMA8491QR1/?qs=%2fha2pyFadujyDfLlWUGDeECT%2fizTUYUDclHBH9IEEfU%3d
If you want something bigger and mechanical.
http://www.mouser.com/ProductDetail/E-Switch/TM1000/?qs=sGAEpiMZZMtCWdKUURnHj1%252bkvdiUuPvDlfB2tFt2oBI%3d
http://www.parallax.com/Store/Sensors/AccelerationTilt/tabid/172/CategoryID/47/List/0/SortField/0/Level/a/ProductID/722/Default.aspx
How about a homemade one from Forrest M. Mims III?
The one Andrew mentioned, the Memsic sensor from Parallax, is very rugged--no moving parts. It detects the distribution of a bubble of warm gas inside a tiny chamber.
(I do like that one from Forrest Mims!)
Does your product have a mcu?, more info could help.
Freescale's IC does do negative G to detect upside down, but the Tilt Detection Output's are absolute values, eg -1 = 1
I think you should only get a 0 if the item is upside down (135deg to 225deg)