Quick Answer: Telegraph Tapping Key is a hand-operated make-and-break switch for low-voltage circuits, used to send short and long electrical pulses, the dots and dashes of Morse code, to a connected buzzer, sounder or lamp.
Last updated: October 2026
Key Features
Lever-operated key that closes the circuit when the knob is pressed and opens it when released
Momentary contact action, so the circuit stays closed only while the key is held down
A brief press gives a dot; holding the key down longer gives a dash
Works with a separate buzzer, telegraph sounder or indicator lamp to give the signal
For current-limited, low-voltage supplies only; never for mains
Technical Specifications
Specification
Value
Product type
Manual make-and-break electrical key
Primary application
Morse-code and telegraph-circuit demonstrations
Switching action
Momentary contact
About This Product
Wired in series with a low-voltage supply and a receiving device, the key lets students tap out letters from a Morse-code chart and see how mechanical contact controls current. Two keys with suitable receivers can be arranged as a simple wired link between two stations, a practical way for Electrical And Electronics classes to explain how the electrical telegraph worked.
Frequently Asked Questions
Q1. Does the Telegraph Tapping Key make a sound by itself? No. It only opens and closes the circuit; a buzzer, sounder or indicator lamp connected in the circuit gives the audible or visible signal.
Q2. How are dots and dashes produced with the key? A brief press of the lever gives a short pulse, read as a dot. Holding the key down longer gives a longer pulse, read as a dash.
Q3. What comes with the tapping key? One Telegraph Tapping Key. The battery or power supply, buzzer, sounder, lamp, connecting leads and receiving telegraph unit are not included unless stated.
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