Pentex production unit: B switch, 1965-1971
1965-1971
General Post Office Type B landline telegraph relay capable of regeneration
1880-1920
Telephone Relay
1925-1935
Type GF Telephone Relays
1915-1925
Telegraph relay (1920s)
1920-1930
Westinghouse bell-jar signalling relays from Glasgow Underground Railway
Single-element relay
Wireless Telephone Relay
1915-1930
Earth Leakage Relay
1940-1960
Westinghouse bell-jar signalling relays from Glasgow Underground Railway
AC Relay
Western Union combination Wheatstone relay
1915
Siemans Polarized Relay
1890
Original Swedish "Birka" bimetal relay with heating coil
German "Birka" thermo-electric "wire-type" (no bimetal) relay in vacuum tube
Hermetically sealed relay
Relay by ATM, 1915
1915
Gulstad vibrating relay
Siemens compound relay, 1876
1876
Relay, devised by Professor Wheatstone, c. 1838
1838
Early pattern relay by A. Reyrolle and Co. Ltd.
1920-1950
Ferranti astatic voltage relay
Non-polarised relay
Ferranti astatic voltage relay
Relay, calling and clearing
Telegraph relay (1920's)
1920-1930
Overcurrent relay by Reyrolle, no. 142568
Ferranti capacitor control
Slow acting relay
Laws Relay as used in early RAE RTV 1
Single point telephone relay 1908
1908
Siemens high speed relay with dust cover
Westinghouse bell-jar signalling relays from Glasgow Underground Railway
Miniature microphone relay
Telephone relay
1915-1925
American 2 pole relay
Polarised relay
Telephone relay by S. G. Brown
744 relay no. 594
Allan and Brown relay
AC Relay; Model 2A
Ferranti model FR under current relay
Ferranti type FS relay
Relay 556
Relay set associated with allotter circuitry and timeout / fault alarms
Western Union polar relay 17B, dated 14.12.1915
1915
Dash-pot relay, for timing delays (1920's)
1920-1930
Magnetic Relay as used in RAE RTV 1
G.P.O type 600 relay
