What is the function of an electronic keyer?

An electronic keyer is a specialized circuit used by Morse code (CW) operators to generate perfectly timed code elements. When connected to a dual-lever paddle, it automates the creation of the code's basic building blocks. Pressing one paddle lever produces a continuous string of 'dots' (dits), while pressing the other produces perfectly proportioned 'dashes' (dahs). Squeezing both simultaneously can alternate them, a technique known as iambic keying. This automation drastically reduces operator hand fatigue and ensures highly consistent element lengths compared to a traditional straight key. It should not be confused with a computer interface used for digital modes like RTTY or PSK, which serves an entirely different purpose.