hello I want to create a telephone board for using in elevator work with two voltage +12 and +24 volt.
and connected two wire from communication

 

Before any design concepts can be created we need a more detailed description of what
"Build an Emergency Telephone PCB for Elevator "
means to the Thread Starter! An Emergency phone system could consist of two handsets, wire, and a single battery. OR a load of MSA-Certified emergency phone packages. About $10,000 difference. At least.

 

We need a LOT more information.

How tall is the elevator?
Is the elevator already wired for telephone communication?
Does the telephone interface with an external phone system, or only a security desk?

ak

 

In addition to the good points made in post #3, there are a bunch of rules about everything associated with elevators, and a lot more than those if the elevator can be accessed by the general public.

 

hello I want to create a telephone board for using in elevator

Where are you located?

ak

 

What are the +12 V and +24 V sources? Is +24 V intended for the telephone circuit? Is +12 V for a separate microphone/speaker circuit?

 

The simplest? A wireless link.

 

The simplest? A wireless link.

There is nothing at all simple about a wireless link. AND they are seldom "private" links. Each end of the wireless link must have both a transmitter and a receiver, both having power source requirements.

 

If it is for emergency calls only, it could be straightforward without need for much privacy.
But we would have to know the exact requirements, which the TS hasn’t yet provided.

 

I have an "elevator emergency phone", which is a lot like an ordinary phone, with a tone dialing option. BUT it is programmed to dial a local emergency number. It is presently somewhere in my storage unit. If I find it I will pas it on to somebody. But I don't know how to change the number it calls.

 

If this emergency telephone is to be connected to the public telephone network, a lot of requirements from standardization organizations like FCC, ETSI, or whatever country you live, have to be taken into account. This is not trivial. On the other hand, an "emergency" phone needs additional features concerning safety and availability even under failure conditions. That is not a trivial task!

 

We certainly need more than:" hello I want to create a telephone board for using in elevator work with two voltage +12 and +24 volt and connected two wire from communication .
This could indeed be a very simple two-handsets arrangement like I made when I was a kid, up to an autodial MSA-certified system.
HOW does the 12 and 24 volts relate to an emergency phone system??? AND who would the auto-dial actually call???