Abstract: A control for use with pressure-sensitive devices, such as in a machine-guarding application. A plurality of pressure-sensitive devices, such as pressure-sensitive safety mats, are operatively connected to produce a disable signal and a status signal. An activation module produces a switching output responsive to the disable signal and the status signal to disable a machine. In one embodiment the status signal is produced by a comparator in response to a quantity selector and a quantity indication signal produced by the pressure-sensitive devices. In the preferred embodiment, the control system of the present invention is able to detect proper safety mat configuration, whether a threshold pressure is being applied to a pressure-sensing region in the plurality of safety mats, and whether the quantity of operatively coupled safety mats conforms to the quantity specified to be deployed.

Abstract: A light source controller having a look-up table that indicates the amount of current to be provided to a light source to maintain wavelength and spectrum stability at various temperatures. Further, the light source may have a heater/cooler to maintain a constant temperature of the light source. The controller provides the appropriate current to the light source from the time of turn-on until it achieves thermal equilibrium, to provide an output having a relatively constant wavelength during the warm-up period and during changes of ambient temperature about the light source. The light source may have a heater and/or cooler to maintain a constant ambient temperature, so that the light source controller can provide a more refined control of the light source output wavelength and spectrum. The light source controller may be particularly used for a light source in a fiber optic gyroscope.