BUZZER No. 20

A buzzer for general purpose use.

The early version is shown above (Marks 1, 2 & 3) and is constructed of wood and steel, whilst the later, Mark 4 version, is made of plastic.

Working voltage is 10 - 50v DC.

It is fitted with R.F. suppression called a Filter, Suppression No. 12.

Buzzer No. 20A - Consists of two 1,000ohm coils that can connected in parallel or series - 50 volts DC.
Buzzer No. 20B - Consists of two 50ohm coils that can connected in parallel or series - 2-10 volts DC.

Dimensions - 89mm x 86mm x 38mm.

Drawing - 62799.

Specification - S594.

Similar to Buzzer No. 18.

Some were produced by ETL, their Part No. N3349.

Last revised: July 23, 2025