Design Project Help: Electrical Resistance Measuring Device

[shewdz]

Hi all,

im looking for a bit of help and advice. I am currectly carrying out a design profect that has the following brief,

a device that measures a change in electrical resistance using a therminstor, pressure sensor (QTC pills), or a light sensor and uses an LED and/or buzzer as an output

it has to be hand held.

not currently availible on the market.



these are the only real factors that affect the design of the product.


the help i require is thinking of possible devices or applications. the device can be a novelty toy, technical device... just about anything. i feel there must be some great ideas out there, I am just struggling.

so far i have thought off...

continuity tester for household use

baby bottle that lights up when the contents is too hot

novelty coatser that lights up when a drink is placed on it


any help would be much appreciated.

Adam

 

[MATLABdude]

What's wrong with those applications? Maybe you could make it fit on the tip of your finger (like a thimble) and tell you when a surface is hot or not. I'd make the LED blink proportional to how hot it is though (i.e. if it's solid, it'll for sure burn you, if it's blinking slowly, someone's probably got a fever).

The device itself would be pretty easy to implement with at a small microcontroller, LED and thermistor. Might need an extra resistor, op-amp, and probably a battery and/or voltage regulator.