A telegraph circuit is an electrical circuit attached to a telegraph. This circuit is incomplete until the telegraph is connected, allowing for the Morse-code messages by tapping the circuit closed.
A relay circuit is typically a smaller switch or device which drives (opens/closes) an electric switch that is capable of carrying much larger current amounts. Or a circuit which operates the coil or electronic actuator from one source and uses a separate power source to drive an isolated device. Generally speaking, a relay circuit is a circuit that uses a small mechanical switch or a semiconductor device (with associated circuitry) to energize a relay, which will then close a contact set to complete another circuit. This system is used by most people on a daily basis, and it is used to start a motor vehicle. The key switch (ignition switch) is turned to "start" and 12 volts (approximately) is applied to the starter solenoid (which is a big relay). The coil is energized, it shuts contacts, and the battery voltage is delivered through the heavy contact set (for high current capacity) to the starter motor. There are variations on this theme to which the term relay circuit can be applied, but the idea remains the same: a small switch of some kind controls switching in another (usually higher voltage and/or current) circuit. It could be argued that the telegraph is a relay circuit. Remember those old westerns? When a telegraph key is pushed down (thus completing the circuit), a remote (relay) coil is energized. The magnetic field created by energizing that coil pulls down an armature with the objective being to make a "click" instead of it being to close some electrical contacts. An early and dramatic application of the simple relay circuit, the telegraph, yes? A RELAY CIRCUIT DOES NOT IMPLY MASSIVE CURRENT SWITCHING. It is a means to isolate one source to another.
no, just wireless telegraph
Telegraph invented
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An open circuit or a short-circuit (if that circuit is complete).
a transmitter that sends out morse code signals
THe telegraph key is a switch. Tapping it closes a circuit and send a pulse of electricity down the line. These taps are used to code messages.
A single wire telegraph used (earth) ground to complete the circuit. A single wire is run from the key to the receiver, and the other half of the circuit is completed by driving a conducting rod into the ground at each end. Runs of over 2 miles have been tested using this technique.
The return path is through the Earth. That's called the "ground" connection.
induce an electrical charge and then sends it across a wire to its destination
telegraph changed to internet
Telegraph-Journal was created in 1862.
Yes a telegraph can be wireless. Thomas Edison invented the first wireless telegraph
The Barclay brothers puchased the Telegraph Group , which included the The Daily Telegraph, Sunday Telegraph and The spectator, from Hollinger in 2004.
The telegraph.
The telegraph key, an essential component in early telegraph systems, was developed by Samuel Morse and Alfred Vail in the 1830s. They created the device as part of the Morse code system, which allowed for the transmission of messages over long distances using electrical signals. The key itself is a simple switch that opens and closes an electrical circuit, enabling the transmission of dots and dashes that represent letters and numbers.
HOW THEY MADE A MORSE CODE MACHINE Samuel F.B. Morse and Alfred Vail developed an electric telegraph which sent pulses of electrical current to control an electromagnet that was located at the receiving end of the telegraph wire.