If you are continuing to revise, I noticed a mistake in the safety chapter when you said that telephone ring voltage is 48V. In fact, US phone systems use -48V battery but ringing is often 130V 20Hz AC or variations of.

The series is great and I have used it as a resource to train my employees. WELL DONE!!

 

If you are continuing to revise, I noticed a mistake in the safety chapter when you said that telephone ring voltage is 48V. In fact, US phone systems use -48V battery but ringing is often 130V 20Hz AC or variations of.

The series is great and I have used it as a resource to train my employees. WELL DONE!!

Hi CATV,

Can you provide a link to the chapter you are refering to?

Dave

 

http://www.freepatentsonline.com/4653087.html lists: "When an incoming telephone ring signal is applied to the terminals 102 and 104 (typically being at a value of approximately 150 volts and 20 hertz)"

I have changed the Vol 1, DC, Safety chapter to read 150 Volts. If anyone finds this to be incorrect, please le me know. I am not a telephone expert.