RPM meter

The 555 gives a time frame of 10 seconds of measuring revolutions. The UP counter stops automatically after that period of time and shows the amount of revolutions . BUT... the 555 must have a 9.12M Ohm resistance and a 1uF capacitor for exactly 10 seconds in the real world. BUT... In this virtual simulation it doesn't function with precise math!!!. 2nF give a time frame of 14 seconds...that suXXX! Eventually my iPad 2 is getting too slow too... BUT... I consider this easy circuit app not authentic and not too accurate . The frequency sources do not work precise either. Besides the time frame gets strongly affected by the RPM source which is to measure! That is physically AND even mathematically absolutely incorrect! LETS SAY ABSOLUTELY >WRONG< !!!!!!!!!!!!!! That suXXXX But this circuit works just fine. If you want to build it you will have to take above mentioned values for the RC or do the real world math! Have patience, have fun.

published 11 years ago