telephone ring detector

[highlander11]

I searched in these forums telephone ring detector I found circuits ( like :


but my question is what is the difference between simple circuits like the link and telephone ring detector like mc34012, mc34017

whats better ?

 

[pranam77]

I searched in these forums telephone ring detector I found circuts( like : . but my question is what is the difference between simple circuts like the link and telephone ring detector like mc34012, mc34017 whats better ?

It all depends in which way you need to detect the ringing on a telephone lines. The way mentioned in the given link is using an optocoupler which osolates the telephone line from the circuit on the second side which is naturally safe for both the sections. ie the telephone side as well the dc side.
The MC34012 what you have mentioned are ringer Ic's used in telephone instruments which when connected to the telephone lines in conjunction with other biasing components as suggested on the device datasheet, will deliver an audible output through a piezo element or a speaker, with a high frequency which audibly detects the ringing of the telephone...Cheers