Latest update to schematic. Have tried to minimise the loading of the phone line, replaced large 2.2uf/400v cap for 0.1uf/400v. Both the ring detector and off hook detector have a certain symmetry, they are very similar. Use of 10v zener and voltage divider to get new knee point.
Latest update to schematic. Have tried to minimise the loading of the phone line, replaced large 2.2uf/400v cap for 0.1uf/400v. Both the ring detector and off hook detector have a certain symmetry, they are very similar. Use of 10v zener and voltage divider to get new knee point.