# LM2917 - to measure between 0 to 10Hz

Discussion in 'General Electronics Discussion' started by Bel_Esprit, Nov 7, 2012.

1. ### Bel_Esprit

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0
Nov 7, 2012
If anyone could help i would gladly appreciate it,

I am trying to design LM2917 to rotor speed of a turbine and wind speed, using one of the AC lines from a three phase
So for the rotor speed i need to measure between 0 and 600rpm, i looked at couple of LM2917 voltage to frequency circuit, but they output high Hz/V,

What can i used to calculate the resistor or capacitor that i need to design a LM2917 that can measure between 0 to 10Hz? Can anyone point me to the direction with formulae or just let me know what capacitor or resistors i need and pin configurations? would really appreciate it.

Is it also maybe to get the frequency (then rotor speed) directly using a National Instrument DAQ Card, by just stepping down the voltage using a voltage divider?

2. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

25,497
2,838
Jan 21, 2010
Look at the datasheet. See page 7. Bottom left corner.

Aren't datasheets wonderful!