BI-RISTOR

VARIABLE POWER CONTROL APPARATUS-NAMELY, ELECTRIC CIRCUIT CONTROL UNITS OF THE SOLID STATE TYPE FOR CONTINUOUSLY VARIABLE ADJUSTMENT OF ELECTRIC POWER TO LOAD DEVICES, FOR USE IN CONNECTION WITH ELECTRIC LIGHTING, HEATING AND AIR CONDITIONING EQUIPMENT, ELECTRIC APPLIANCES, POWER TOOLS AND FLOOR SERVICE EQUIPMENT; PARTS OF SUCH CONTROL APPARATUS, AND ACCESSORIES USED THEREWITH