Abstract: An ultrasonic welder includes dynamic adjustment of a weld parameter used to control welds of weld cycles during serial operation of the ultrasonic welder. The ultrasonic welder includes a power supply controlled by a controller and the controller sets a value of the weld parameter for a next weld cycle based on a value of a stack heat energy parameter indicative of heat energy in the ultrasonic stack prior to beginning the next weld cycle. The controller controls the power supply based on the value set for the weld parameter to control a weld in the next weld cycle.

Abstract: An ultrasonic welder includes dynamic adjustment of a weld parameter used to control welds of weld cycles during serial operation of the ultrasonic welder. The ultrasonic welder includes a power supply controlled by a controller and the controller sets a value of the weld parameter for a next weld cycle based on a value of a stack heat energy parameter indicative of heat energy in the ultrasonic stack prior to beginning the next weld cycle. The controller controls the power supply based on the value set for the weld parameter to control a weld in the next weld cycle.

Abstract: A fluid control valve 1 comprising a valve body 2 having a central bore 4 provided with a plurality of radial apertures defining inlet and outlet ports 5,6,7, and a spool slidably mounted within the central bore for axial movement therein to provide selective fluid communication between selected pairs or groups of the inlet and outlet ports, wherein at least one annular groove 14a,14b,14c is formed in an outer periphery of the valve body in the region of one of said radial apertures, a filter 12 being provided in said at least one annular groove, the filter comprising a perforated plate or membrane formed into a cylindrical shape and located in the annular bore, the perforated plate being held in place in the groove by retaining means 16, wherein the retaining means 16 comprises an elongate resilient member located around the outer periphery of the perforated plate and adapted to apply a compressive biasing force against the plate, free ends of the elongate resilient member extending substantially tangential