Abstract: A control circuit for controlling the fan or circulating pump in a solar-thermal heating system to prevent unnecessary pump or fan switching when short-term interruptions occur in the insolation of the solar panels includes a temperature-sensitive time-delay element tailored to have thermal response characteristics corresponding to those of the solar panels in the system.

Abstract: A solar-heating system incorporating a photosensitive sensor locatable remotely from the collector panels but similarly oriented with respect to the solar-energy source, such photosensitive sensor being biased by one or more biasing resistors of predetermined magnitudes and temperature coefficients so that the combination, in its performance with respect to ambient temperature and (optionally) with respect to ambient wind velocity, matches the thermal characteristics of the solar energy collection system so that the solar-energy collection fluid is pumped only when it can contribute heat energy to the already stored solar-heated fluid.

Abstract: A device, and controlled solar heating system incorporating the device, for providing an electrical control signal responsive to the rate of flow of species of radiant energy through an area. The device includes means for providing an electrical input signal responsive to the rate of flow of the species of radiant energy, such as solar energy, and an electrical circuit for receiving the input signal and for providing a control signal in response to the input signal. Solar cells may provide the input signal to a Schmidt Trigger Circuit set to provide two control signals at predetermined rates of solar energy flow through an area. The device, incorporated into a solar heating system, may be used to control the circulation of fluid through solar heating panels.

Abstract: A direct current power supply system for providing power, including standby, to coaxial cable amplifiers in community antenna television networks. Alternating current is rectified and used to power coaxial cable amplifiers spaced along the cable and to maintain a full charge on a storage battery which is continually connected to the input of the cable. In the event of failure of the commercial primary power source, the battery feeds power to the cable amplifiers. Provision may be made for selectively reversing the output of the power supply to insure that there will be no corrosion deposits caused by electrolysis. Finally, the invention also provides circuitry for protecting the storage battery from excessive discharge during power failures of long duration.