Double focus solar collector - heats an oil filled heating circuit and has photoresistors to position dish through hydraulic cylinders controlled by operational amplifier

摘要

The solar collector has reflecting segments fixed to a polystyrene dish to form a dual focus heating of a closed oil circuit which is used to heat water. The orientation of the reflector dish is determined by photo resistors mounted on the dish which use an operational amplifier circuit to maximise the light intensity at the focus. The operational amplifier circuits control a hydraulic cylinder which through rack and pinion drive of a chain coupling positions the dish in the horizontal plane. A hydraulic cylinder connected to the lower half of the dish pivots it round the horizontal axis to give vertical orientation. A photo resistor is used to sense illumination level and to control the flow of the oil working fluid in response to the light level.