The present invention involves a light system for stimulating or regulating neuroendocrine, circadian, and photoneural systems in mammals based upon the discovery of peak sensitivity ranging from 425-505 nm; a light meter system for quantifying light which stimulates or regulates mammalian circadian, photoneural, and neuroendocrine systems. for a long time period A heat-setting type epoxy resin is employed. A printed portion is made by printing on the portions other than the film 20 of the support 10 in substantially the same color as that shown when the film 20 is viewed from the front. The former includes transmitting a hole exchange message periodically, pseudo-periodically, or according to a timer expiry. The embodiment of the circuit and method disclosed herein include novel implementations of a time-slot interchange circuit and a telephony signaling circuit.