Abstract: A photo controller circuit for use in hazardous areas has an output switching (OS) circuit comprising an alternistor for ON/OFF switching of a load, and an optoisolator for gating the alternistor. A light to voltage converter (LVC) circuit generates a DC voltage proportional to detected incident light. A hysteresis control (HS) circuit comprises a voltage comparator for generating an output depending on the DC voltage and the state of the OS circuit. An integrator and switching (IS) circuit turns on and activates the optoisolator when the output of the HC circuit indicates the detected incident light is below a selected level, and turns off and deactivates the optoisolator when the output of the HC circuit indicates the detected incident light is above a selected level. The IS circuit time delays the output of the HC circuit prior activating or deactivating the optoisolator. The electronic components are rated for 125° C.

Abstract: A locking assembly for a ballast housing simply and easily locks a lid to a body of the housing. The body has a first base and a first wall extending upwardly from the first base. The lid has a second base and a second wall extending downwardly from the second base. A tab extends outwardly from the first wall. A fastener is pivotally disposed in an opening in the tab, and has a head adapted to receive a rotating device. A third base extends outwardly from the second wall. A slot in the third base is adapted to receive the fastener. A nut is threadably disposed on the fastener and the fastener is rotatable through the nut to engage the fastener head with the tab and to engage the nut with the base to tightly secure the lid to the body.