Abstract: A heating system is controlled in response to the external temperature in accordance with a heating curve in which the external temperature is related to the advance heating temperature of a fluid used in heating the space. According to the invention, the heating curve is optimized automatically by approximating it with a heating curve equation having at least one parameter which is calculated at least in part from measured instantaneous values of the advance heating temperature, the external temperature or the room temperature, or values representing temperature differential such as the difference between the external temperature and the room temperature and the difference between the room temperature and the advance heating temperature. From these values, a parameter of the heating curve equation is calculated by an estimation method, e.g.

Abstract: A system for the control of a load such as a heating or cooling plant in response to changes in an external parameter, specifically ambient temperature, comprises a loop circuit with two conductors connected at an input end across a power supply and at an output end across a switching network, the load being inserted in one of these conductors. A high-impedance voltage multiplier connected across these conductors downstream of the load, in parallel with the switching network, supplies the necessary operating voltage to a parameter sensor such as a thermostat even when that network is in a low-impedance state so as to draw a maximum load current. The switching network may include a voltage clamp provided with a source of reference potential, e.g. a primary battery, which upon failure of the normal power supply can act as a standby supply insuring continued operation of a timer serving for a periodic switchover between different temperature thresholds for the thermostat.

Abstract: A system for alternately activating and deactivating a load comprises a high-resistance d-c circuit branch connected across a power supply downstream of a load-operating impedance, this branch including a voltage limiter and a voltage multiplier in series with each other and with a switching stage responsive to commands from a timer and/or a parameter sensor such as a thermostat. The junction of the voltage limiter and the voltage multiplier is connected to one input of a differential amplifier whose other input is energized with either of two potentials, respectively higher and lower than that of the junction, by the switching stage.

Abstract: In order to ascertain the magnitude R.sub.i of an unknown resistance element in digital terms, two calibrating resistances of known magnitudes R.sub.1 and R.sub.2 =mR.sub.1 (with m>1) are connected in circuit with a capacitor, to form a switchable RC network, during two gating periods whereas the unknown resistance element is inserted in their place during a third gating period. A multiplicity of counting pulses are fed during each gating period to a pulse counter delivering their count to an arithmetic unit which determines the ratio R.sub.i /R.sub.1 from the several pulse counts and from the factor m. The switchable RC network may be part of a one-shot pulse generator, establishing a variable gating period for counting pulses of a fixed cadence, or of an astable multivibrator generating different counting pulse rates during gating periods of constant duration.

Abstract: A programmable memory for the automatic control of a heating or cooling plant over a 24-hour, 7-day or longer cycle comprises a frame with a multiplicity of mutually parallel printed-circuit strips whose major surfaces carry two sets of conductors arrayed in an orthogonal matrix, the strips being overlain by a cover plate with slits for the insertion of jumpers bridging selected conductors at their points of intersection. The conductors of one set are sequentially energized while those of the other set are rapidly scanned to detect an output signal representing a selected time in the program cycle at which a command for a change in thermostat setting is to be emitted. The cycle is established or modified by a program plate superimposable upon the cover plate to block some of its slits and/or to actuate one or more switches correlating the several matrix outputs with respective clock readings different for the various cycles.

Abstract: An arrangement for controlling room temperature in conjunction with a heating or air conditioning system which operates throughout successive and uniform periods of time, each period of time being divided into a first time interval and a second time interval and including a first computer for a rapid heating or rapid cooling curve and a second computer for computing an actual value room temperature curve in accordance with input data including outside weather conditions, building value etc., the heating or air conditioning system being switched off at the beginning of the second time interval and switched on at a predetermined instant during the second time interval thereby effecting a substantial savings in energy.

Abstract: A program storage device which can be variably programmed manually. The device comprises for this purpose at least one printed circuit board having primary electrical contact surfaces and at least one secondary contact surface; a transverse board with a row of slits for each circuit board; and slide contacts which are designed for insertion into any of the slits in the transverse board for electrical connection, according to a desired program, with the primary and secondary contact surfaces.