GB577744A - Improvements in or relating to temperature regulating installations - Google Patents

Abstract

577,744. Telecontrol of temperature regulating installations. LANDIS & GYR SOC. ANON. Oct. 20, 1942, No. 14673. Convention date, Nov. 24, 1941. [Class 40 (i)] In a system in which a thermostat is provided with an auxiliary heater 3, the current through the latter is controllable from a number of different stations a, b and c. A station gets control by operating its key D which on depression closes its upper earlier than its lower contacts and on release opens its lower contacts before its upper ones. On the operation of D therefore the re-setting coil of the local relay R, which is of the type having no bias springs &c. is energized and remains energized when, shortly afterwards, the operating coils of the relays R at all the stations are energized since the resetting coil overpowers the actuating coil. In these conditions, the local relay is not actuated but the others are and in consequence all the regulating resistances W, which are connected in series, are shunted out except the local one which can then be used for exercising a desired control on the auxiliary heater 3. The release of the key makes no difference since the local resetting coil is held energized until after the circuit of the operating coil has opened. The Specification as open to inspection under Sect. 91 comprises also a system in which a number of thermostats are selectively controlled from a single station. The system forms the subject-matter of Specification 580,959 and is not included in the present Specification as accepted.