hi, i need to build a voltage indicator. when i am in the voltage range the led will be green, when i am outside the range the led will change its color. which part shoud i use to get this done?
I recommend the TPS3700. It is a window comparator. The output will be one state if the voltage is within the window. The output will change states if the voltage is outside of the window. You simply need to use the input to drive the LED.
is there any wider window?
i need the window to be 12V to 40V
I hope you can find what you need.. basic comperators: http://home.cogeco.ca/~rpaisley4/Comparators.html
For the TPS3700, the window is set with three external resistors. The lower limit of the window and upper limit (and the difference between) can all be adjusted to any value.
Hi Alon,
The TPS3700 datasheet has design equations on page 11. Also, there is an available EVM to help test the TPS3700 in your application.
http://www.ti.com/tool/tps3700evm-114
Regards,
Darwin