I decided to start my writing on Habré with a very simple, but useful project that has been living in my house for many years.
Gave me somehow an ancient phone. It was released, if not under Joseph Vissarionovich, then under Nikita Sergeyevich, for sure! Approximately then Gagarin flew into space. In general, the thing is cool! You can certainly put on the shelf "in the museum", but somehow not interesting. And the days of wired phones are long gone. It is necessary to give the device some functionality so that you can use it. I decided to make him an intercom. So:
To begin with, we will study the typical scheme of a tube of a coordinate-matrix intercom (I have exactly this and the scheme is very similar). Pictures are clickable.
Redoing is not a problem. Only there are a couple of moments:
- The speaker and the call do not have a common wire. So, the native 3-wire cable from the phone will have to be replaced with 4-wire (for example, a good USB cable).
- The loudness of the speaker in the handset of the phone is hardly enough to squeak for the whole apartment. So the call will have to be made separately in the phone.
So, disassemble the phone and throw away the excess giblets.
We need to leave: a dialer, a lever tube with contacts, pads for easy connection. Well, the handset with a microphone and speaker by itself. Speaker and microphone should be checked, connect 4-core wire to the handset. Clean and check the contacts of the dialer and the lever of the tube.
From the doorphone tube, leave the board and speaker. The speaker is used as a call.
Now we collect
The tube is connected to the corresponding contacts on the intercom board.
The call (speaker from the doorphone's tube) is fixed to the phone case and connected via the contacts of the tube lever (purple color on the diagram).
When the handset is down, the contact is closed and the bell is on. When the handset is lifted, the call is disconnected and the intercom comes into play.
As a button to open the door, connect the dialer
He has at least 2 groups of contacts. Some read the numbers (provide an interrupt when the pulse dialing), but we do not need them. We are looking for those who lock up when the disk is rotated.
We type any number on the disk, the contacts close, the door opens.
To the switch SA1, I soldered the jumper just for reliability.
Reed switch SA2 is not involved.
We collect everything, we check, we connect.
Intercom has polarity! See the diode at the entrance? Do not confuse plus or minus!
Rejoice, enjoy the view
Phone on the shelf fits into the design of the hallway is much better than the miserable white tube near the door. And the sound of the carbon microphone is the same!
Guests are surprised and ask questions.
In this way, you can alter any disk phone. So hurry to search the basements, storerooms and attics!
In general, I congratulate everyone on Friday! Hooray!