Once i filter the data using RC filters, i pass it through opamp comparator for wave shaping. The output of opamp is 24V peak to peak(+12v to -12v with a centreline of 0, i.e. VDD=+12v and Vss= -12). I attenuate it to 10 V pk to pk (5v to -5 v) using voltage divider resistors R12 & R13. Then i clip the negative part using diode D6. Ideally, this arrangement should give me an output across R14 that varies from 0 to 5v( TTL levels for microcontroller).
But in reality, the output is not clipped, that is, it's still a signal varying from 5v to -5v(10v pk to pk). Can u tell me why??
**broken link removed**
Is there any other way of getting 24v(-12 to +12v) signal to TTL level??