Where can find FSR-402?..

[Fiz]

Its fine for me to use DIY FSR, the project dont have to work properly and exactly as its stated.

About the output,what the best indicator should i use?
thx for continues response~~

[ABSF]

Use 10 LEDs connected to LM3914 or google for "Window comparator"

Allen

[Fiz]

Oh thx,really thx
All your answer is satisfying

[Fiz]

A little more help here..
What the window comparator actually doing?
I'm quite slow here.

[ABSF]

A little more help here..
What the window comparator actually doing?
I'm quite slow here.

You can think of window comparator as an analog version of address decoder like 74138 or 74145. The 74138 will decode 3 bit binary data "000 to 111" to turn 1 out of 8 outputs low.

The window comparator here
http://ecelab.com/circuit-window-comp.htm
will produce a low output when the Vin is in between Vref (high) and Vref (Low)

In Page 7 of the datasheet of LM3914. You can see that LM3914 is a window comparator too.
http://www.energies.alba-annuaire.fr/data/lm/LM3914.pdf
By connecting 5V to RHI, the comparator will divide the V sigin by 10. Each increament of 0.5V will light up one LED linearly.

Allen