Hello,
I know this subject has been discussed numerous times but I need some guidance on building a tach circuit. The circuit will have input frequencies between about 30Hz-500Hz.
Ideally, the IC will be powered from the car's 12V system but having done a bit of reading, I heard it was best to regulate the car's voltage using an LM7805 with filtering caps to about 9V.
I have scanned through the LM2907/LM2917 datasheets and I need some guidance on which chip to use. I'm not an expert in electronics and I know that the LM2917 has a built-in zener diode.
I have also downloaded some models of the LM2907 and LM2917 for LTSpice. I need help choosing appropriate values for the resistors and capacitors.
Ideally I would like to have an output of 0-5V so I can input it into an ADC port on a microcontroller.
How should I start???
Thanks.
I know this subject has been discussed numerous times but I need some guidance on building a tach circuit. The circuit will have input frequencies between about 30Hz-500Hz.
Ideally, the IC will be powered from the car's 12V system but having done a bit of reading, I heard it was best to regulate the car's voltage using an LM7805 with filtering caps to about 9V.
I have scanned through the LM2907/LM2917 datasheets and I need some guidance on which chip to use. I'm not an expert in electronics and I know that the LM2917 has a built-in zener diode.
I have also downloaded some models of the LM2907 and LM2917 for LTSpice. I need help choosing appropriate values for the resistors and capacitors.
Ideally I would like to have an output of 0-5V so I can input it into an ADC port on a microcontroller.
How should I start???
Thanks.