dramrattan
Member
Hi,
I am trying to detect a ring and send it to a PIC18F452. I used the first circuit on the link below and getting approximately 3.85V at the output everytime the phone rings. I was getting 5V at the output when i have C2 = 10uF but the time constant formed by C2 & R1 to reduce the voltage back to zero volts was too long (1s) and causing conflict with the PIC18F452.
I changed the capacitor to a 1uF so the voltage would reduce back to zero volts in 0.1 seconds but the voltage at the "ring detect" now drops to 3.85V everytime the phone rings.
How do i keep the time constant at .1 seconds but have the ring detect voltage at 5V?.
I am trying to detect a ring and send it to a PIC18F452. I used the first circuit on the link below and getting approximately 3.85V at the output everytime the phone rings. I was getting 5V at the output when i have C2 = 10uF but the time constant formed by C2 & R1 to reduce the voltage back to zero volts was too long (1s) and causing conflict with the PIC18F452.
I changed the capacitor to a 1uF so the voltage would reduce back to zero volts in 0.1 seconds but the voltage at the "ring detect" now drops to 3.85V everytime the phone rings.
How do i keep the time constant at .1 seconds but have the ring detect voltage at 5V?.