A crank telephone is an antique device that allows two people to communicate with each other via wired connection. In this article, we will discuss the wiring diagram of a crank telephone, its components, how it works and how to set it up. A wiring diagram is a graphical representation of an electrical circuit. It shows the components of the circuit as simplified shapes, and the power and signal connections between them.
Components of a Crank Telephone
A crank telephone consists of several components, each of which performs a specific function. These components include:
| Component | Function |
|---|---|
| Battery | Supplies power to the circuit |
| Bell | Produces sound when the phone rings |
| Hook switch | Switches the phone on and off |
| Microphone | Converts sound waves into electrical signals |
| Receiver | Converts electrical signals into sound waves |
Each component is connected to others through wires and the wiring diagram specifies how each component is connected.
Wiring Diagram of a Crank Telephone
The wiring diagram of a crank telephone is shown in Figure 1 below. It consists of two parts:
- The talking circuit – this is the circuit that connects the microphone and receiver and allows the two parties to talk to each other.
- The signaling circuit – this is the circuit that controls the ringing of the bell and the hook switch.
| Figure 1: Wiring diagram of a crank telephone |
The signaling circuit is connected to the battery through the hook switch. When the phone is on the hook, the signaling circuit is open and the battery is disconnected, saving its energy. When the phone is taken off the hook, the circuit is closed and the battery is connected, providing power to the circuit.
The ringing of the bell is controlled by a magneto generator which generates an alternating current (AC) when the crank is turned. This AC current is used to ring the bell.
How a Crank Telephone Works
When a person speaks into the microphone, it converts the sound waves into electrical signals which are transmitted through the talking circuit to the receiver. The receiver then converts these electrical signals back into sound waves which can be heard by the other person at the end of the line.
When a person wants to make a call, they turn the crank which generates an AC current that rings the bell at the other end. When the other person picks up the phone, the signaling circuit is closed and the talking circuit is opened. The two people can then talk to each other.
Setting up a Crank Telephone
Setting up a crank telephone involves connecting the components as shown in the wiring diagram. The steps involved are as follows:
- Connect the battery to the positive and negative terminals on the hook switch.
- Connect the magneto generator to the bell.
- Connect the bell to the signaling circuit through the hook switch.
- Connect the microphone to the talking circuit.
- Connect the receiver to the talking circuit.
Once all the components are connected, the phone can be tested by turning the crank and checking if the bell rings and if the two parties can communicate with each other. Any issues can be fixed by tracing the wiring as per the wiring diagram and checking the connections.
FAQ – Frequently Asked Questions
1. What is a crank telephone?
A crank telephone is an antique device that allows two people to communicate with each other via wired connection. It consists of several components including a battery, bell, hook switch, microphone and receiver.
2. How does a crank telephone work?
When a person speaks into the microphone, it converts the sound waves into electrical signals which are transmitted through the talking circuit to the receiver. The receiver then converts these electrical signals back into sound waves which can be heard by the other person at the end of the line. When a person wants to make a call, they turn the crank which generates an AC current that rings the bell at the other end. When the other person picks up the phone, the signaling circuit is closed and the talking circuit is opened. The two people can then talk to each other.
3. How to set up a crank telephone?
Setting up a crank telephone involves connecting the components as shown in the wiring diagram. The steps involved are connecting the battery to the positive and negative terminals on the hook switch, connecting the magneto generator to the bell, connecting the bell to the signaling circuit through the hook switch, connecting the microphone and receiver to the talking circuit. Once all the components are connected, the phone can be tested by turning the crank and checking if the bell rings and if the two parties can communicate with each other.
4. What is a wiring diagram?
A wiring diagram is a graphical representation of an electrical circuit. It shows the components of the circuit as simplified shapes, and the power and signal connections between them.
5. What are the components of a crank telephone?
The components of a crank telephone are battery, bell, hook switch, microphone and receiver.
