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ATM
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Automatic Telephone And Electrical Co. Ltd.
Norfork House
Norfork Street
London
WC2
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Automatic Telephone And Electrical Co. Ltd.
Melbourne House
Aldwych
London
WC2
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Automatic Telephone And Electrical Co. Ltd.
Strowger Works
Liverpool 7
UK
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1940s - 1950s logo
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Post 1958 logo
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Initially the International Automatic Telephone Co. Ltd. Changed their name after
incorporating Automatic Electric Co. Ltd.
The company are exhibiting the "Rythmatic" Control System for the remote control of public lighting and other
services over supply networks (which has only recently been introduced). 24 different switching operations are available. For the control of street lighting,
three operations are required: one for switching-on the lights, the second for switching them off, and the third for
a "half light" condition. The Control and Transmitting Cubicle stands approximately 6 ft. high and has on the face
push buttons for actuating the equipment. - APLE Conference Programme 1938
The Strowger works, Liverpool, was extended. - Public Lighting #14, 1939
The first installation in Great Britian using the Rythmatic Control System is in Falkirk. - Public Lighting #14, 1939
The "Rythmatic" Control System is again being exhibited. In addition to established
features, the push buttons for control can be fitted at any remote point such as the
office of a chief engineer, chief constable, and so on. In addition to the three street lighting
operations, there's the switching on and off of water heating, shop window lighting,
advertising signs, etc. The firm stress its use in peace time but emphasise the use of
this system in times of national emergency. Buttons could be arranged to call out
Air Raid Wardens, Rescue and Decontamination Squads, Firemen, Doctors and Nurses;
and to extingush all street lights and advertisement signs throughout the area.
When the emergency is over, "all-clear" sirens can be sounded and street lights
switched on. "An interesting feature in connection with these emergency facilities is
the development of a portable emergency alarm by means of which controlling
officers or other persons may be summoned to duty. These alarms are plugged into the
mains supply in the homes of persons concerned or in the homes of friends they
may visit or even in the theatre. The alarm unit emits a penetrating audible
signal which persists until switched off."
Injects four different audio frequencies at six different impulse timings. Special
relays in receiving equipment has two essential components: (a) a tuned circuit which
responds to one of the four audio frequencies and (b) two swinging armatures with
natural periodicities corresponding to two of the six impulse timings. - APLE Conference Programme 1939
A demonstration piece shows actual equipment operating in conjunction with a
pictorial representation of a city. Depicted on a diorama are miniature street lamps,
which are operated by means of receiving relays linked to standard self-contained
"Rythmatic" unit for sub-station area control. Two switching facilities are
shown in addition to the control of street lamps: one shows how
Police-call lamps on Street Fire Alarm boxes can be switched "on" from
a central control; and the other demonstrates the switching "on" and "off"
of domestic water heaters for the purpose of peak load control. - APLE Conference Programme 1945
The "Rhythmatic" Centralised Remote Control system is being demonstrated with
a mock-up of a power station control room and a model city with street lights. Prominence is given
to the galvanometer type relay responding only to one predetermined frequency impulsed at
a fixed rate or "rhythm." This dual selective principle of the relay ensures complete reliability
in operation and immunity from interference. - APLE Conference Programme 1946
Demonstrating its new "Rhythmatic" relay called the 46 V.S.. "Rhythmatic" is the most widely used ripple
system in the country and many thousands of "Rhythmatic" replays are being used for the control of street lighting,
load shedding, calls for fire services etc. For some time there has been a demand for a relay of smaller
overall dimensions and lower cost. This demand inspired intensive R&D which resulted in the production of the
new relay, the cubic capacity of which is barely one-third that of the 1936 relay. Because of its small size
the 46 V.S. can readily replace time switches without any alteration to the lamp standards, thus making conversion
to ripple control a more economical proposition both in cost and manpower. The new relay retains the dual selective
principle, the inherent advantages with are: mitigation of "spill-over" problem, immunity from
spurious operation, and economy in production and maintenance. - APLE Conference Programme 1948
The system employs ripple frequency current, normally in the 400 to 1500 cycle band. These currents are superimposed
on to the extisting networks in the form of impulses of various "rhythms" to effect the desired switching operations.
The Rhythmatic control switch, one of which is fitted to each switching point, employs two types of filter,
one electrical and the other mechanical. The electrical filter rejects the 230 volt 50 cycle potential and accepts
the ripple current. The current is then recified and passes through a mechanical filter, which comprises a galvanomenter
relay of special design, the purpose of this beign to prtect the equipment against parasitic voltages and also to
provide an additional means of signal differentiation. The armature of the relay swings under the
control of a spiral clock type spring at a certain fixed and critical periodicity or rhythm. Only when the relay
has recieved a specified number of impulses of the ripple current, timed to be exactly in rhythm with the swinging
armature, deos the armature swing attain sufficent amplitude to close the conact and operate the
associated mechanically locking relay to perform the actual switching operations. The advantage of the system
are:
- (i) The ripple current generating equipment can be of simple and robust type requiring little maintenance.
The frequency generated need not be within close limits as the responding central switch does not depend for its
operation on a critical response to a particular ripple frequency.
- (ii) A wide range of signals is available for a multiplicity of switching operations. As many as 30 different
rhythms may be applied to one frequency with the result that the requirements of a particular area may usually met
with only one frequency.
- (iii) The control switch is of ample sensitivity, being able to respond to a voltage as low as 0.3V and requires
little maintenance, the whole unit being hermetically sealed before leaving the works.
- (iv) The control switches are unaffected by surges, harmonics, transients, parasitic voltages and currents.
- APLE Conference Programme 1949
References:
APLE Conference Programme Bournemouth 1938
APLE Conference Programme Glasgow 1939
APLE Conference Programme Glasgow 1945
APLE Conference Programme London 1946
APLE Conference Programme Southport 1947
APLE Conference Programme Eastbourne 1948
APLE Conference Programme Llandudno 1949
- External Links:
- Grace's Guide
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