Abstract: Lighting apparatus for independently controlling the lighting level in several areas or zones. For example, each zone has two fluorescent lamp units, one connected between the power lines through the contacts of a first low voltage AC latching relay, and the other which produces about half the light of the first connected between the power lines through the contacts of a second relay. Each relay has three terminals. When a low voltage AC signal is applied between a first terminal and a common terminal, the relay is latched closed; and when a low voltage AC signal is applied between a second terminal and a common terminal the relay is latched open. The common terminals of the two relays of each zone are connected together to provide enable connections identifying each zone.

Abstract: Compact monitor apparatus for monitoring a blood circulation condition comprises a radiation source and a radiation sensor mounted in spaced, side by side relation. The source and sensor are placed in contact with the skin and the pulsating blood flow immediately beneath the skin significantly changes the transmission of radiation as a function of the amount of blood flow in that region. Filter circuitry is connected to the sensor and tuned to attenuate artifact signals and enhance the pulsating blood signals. An output indicator responds to the enhanced pulsating blood signals to produce an indication of the monitored blood circulation condition.