I need a transducer or sensor to convert a vibration to electrical pulse.l. possibly called as a vibration sensor for my project..
If you prefer accelerometer can anyone let me know its function or any link..can it be practically used....
i don't know if it helps, but there are pickups for acoustic guitars, that do vibration transducing with piezoelectric parts. maybe you should do some research on them.
There are many kinds of accelerometers. You need to consider your required amplitude range (normally measured in 'g' gravity units), frequency response, and accuracy. Also, do you want to measure one-axis, two-axis, or all three-axis?
Here are some inexpensive MEMS accelerometers from Analog Devices. Maybe one of these will satisfy your needs:
**broken link removed**
There are many kinds of accelerometers. You need to consider your required amplitude range (normally measured in 'g' gravity units), frequency response, and accuracy. Also, do you want to measure one-axis, two-axis, or all three-axis?
thnx to start with,
Actually i want to detect if my roboting unit gets crush by some physical factor .. thats all matters.. and no consideration regarding axes........ what can i use in that place to detect a serious contact with the unit..
regards,
$ujith
Ok, if I understand you want a kind of collision detector.
Fisrt you must know that for any methods there is some limitation for exemple for IR beams it is not possible to detect obstacles that are not opac for light such of glass.
The disadvantage of ultrasound signals is that are easily vanishing. this is not so important because in collision detection you work in close distances. and they present the advantage that you can use the same devise (transducer) for emmiting and receiving.
the principle is that you excite your transducer with an electrical pulse and then you receive the echo you may calculate the time to fleight and then deduce the distance or also the difference of frequency and get if the obstacle is in motion and at whish speed!
If it's interesting you can think about a scanner with us using the properties of spherical spreading of these waves then you can deduce in which direction is there an obstacle.
Regards
just an idea here: you can also use IR emitters and detectors, to check if something is nearby, or even better, there are some acoustic locators, by sharp. this way, you can prevent the collision before it will actually happen
I dont need to detect any obstacles... and i dont need to prevent it from collisions.. all i need s if some thing hits my robotic unit..it must be detected.. that is the controller must get the information that someone has hit the body..
I'm not shure about the english word but try to look for tenso (tension) sensors. They are resistive wire glued on a zig-zag manner over a thin substrate. Every bending that occurs elongate it and it change its resistance dramatically even when you cant notice the vibration.
Assume a car travelling in a road and if it meets any accident the SENSOR must detect that vibration and give an information to the car... what sensor can i use.. any links or details regarding that.....
A vehicle crash sensor is a common application for the Analog Devices MEMS accelerometers (see link above). Are they somehow unsuitable for your project?
You should try to estimate how much acceleration you will be measuring, and its approximate frequency range, and how many axis are required, so you can select a suitable sensor. We can't guess your robot's construction or impact magnitude.
I know this topic is really old but....could someone explain a bit more this?
What amount of vibration does this kind of homemade sensor needs to detect something?
I want to develope an anti-theft system for backpacks jeje. When you are sleeping, you turn it on and "voilá", if someone tries to open your bag the alarm will set off.
I need to make it really cheap. I know that an accelerometer would be the best choice but I'm looking for a simpler solution.