Abstract: A convertible hinge preparation assembly is mounted in hinge cut-outs of a steel door frame or door. The convertible hinge preparation assembly is capable of mounting either regular weight hinges or heavy weight hinges. A plurality of pips are provided for positioning a regular weight hinge. The pips are removed by grinding or drilling when it is desired to mount a heavy weight hinge. In standard weight hinge applications, selective pips, or portions thereof, may also be removed to provide additional adjustment of the installed door and frame assembly to achieve desired operating clearances. The pips are formed by punching the hinge reinforcing member.

Abstract: A pump is driven by a pump motor drive circuit that produces a series of pulse width modulated signals. A closed loop system is included to provide data indicative of any variation in the fluid flow. This is accomplished by using a Venturi located in the fluid flow path to create a pressure differential indicative of the fluid flow. A pressure transducer electronically measures this pressure differential which is then compared to a reference pressure differential indicative of the desired fluid flow. Any variation between the measured and desired fluid flow causes the pump motor drive circuit to vary the width of the pulses that are transmitted to the pump motor.