Accession No

4630

Brief Description

frequency meter, by Elliott Brothers (London) Ltd., English, 20th Century

Origin

England; Lewisham; Century Works

Maker

Elliott Brothers (London) Ltd.

Class

electrical

Earliest Date

1917

Latest Date

1990

Inscription Date

Material

wood; plastic (perspex); metal (iron, brass, steel, other); leather; rubber

Dimensions

height 120mm; width 190mm; length 180mm

Special Collection

Provenance

Donated on 25/07/1997.

Inscription

“ELLIOTT”
“MADE IN ENGLAND”

Description Notes

Elliott Brothers Frequency Meter, of the resonance pattern.

How it works - An alternating voltage is applied to the meter which energizes an electromagnet which operates a soft iron armature rigidly fixed to a spring mounted bar or bars, carrying a number of thin steel reeds. The reeds are adjusted so that their natural period of vibration corresponds to the narrow limits to a definite frequency of the alternating current. The reed (1 of the group) will vibrate in resonance with the alternating current.

In a wooden box with leather carry handle and catch shut lid. On the outside of the box are rubber feet to stand the box both vertically and horizontally and the terminals for power input. In the horizontal position the lid lifts open on brass hinges to display the meter face. Perspex covered, underneath is a metal plate with two slits 135mm wide and 15mm long. In the gap are thin steel reeds bent over at right angles and enamelled white. Above the top slit is a scale 24 to 31 below it the work “FREQUENCY”. Below the bottom slit is a scale 23 to 32 and “CYCLES PER SECOND”. Other marking on the plaste include the inscription above and “No.3044” and “200 VOLTS”

Good Condition

References

Events