Phone call.

░▒▓▌Hello, Max!▐▓▒░ ■30-09-00 at 11:27:38 ■Max Melnikov --> All ■"Phone call." MM> Such a problem, you need to attach a two-tone call to the phone, so MM> I don’t have a diagram, it would take me a long time to come up with it myself, maybe someone can help me? Well, here’s a “tweeter”, the circuit works, it’s been tested. █ <---------------TO LINE------------------> █ │ │ │ │ │ 0.47uF ──┴── │ 250 V ──┬── │ ┌┴┐ │ ┌──────────┐ 10kOhm │ │ │ R │ │ 220 kOhm └┬┘ │ ██████│████████ └───────────┬─────────┤ │ ██ │ █ ┌┴┐ / │ ██ ███│██████ █ │ │ │ / │ ██ ███∙█ █ G ┌───┐ └┬┘ │/ KT3102 │ ██ █████ █ └───┘ │\n │ ██ ██████████ █ 2.2kOhm │ \n │ ██ █ │ │ ██████∙████████ ──┘ │ B │ Piezo element ││ │ (in Chinese tubes) │ └─────────────┴───────── ───────────────────────┘ ──────═════════──────