Abstract: A motor actuator of a climate control system includes an specialized electric motor with a motor housing enclosing an encoder ring on a motor shaft having a plurality of opposite encoder-segment sets with encoder brushes on the housing wiping the encoder ring and thereby forming an encoder circuit through opposite segments of the encoder-segment sets. The electric motor further includes power and encoder terminals positioned externally of the motor housing with at least one power terminal being electrically coupled to one of the power brushes and at least one encoder terminal being electrically coupled to one of the encoder brushes. A control head of the system includes a continuity pulse counter coupled to the at least one encoder terminal for creating pulses representative of impedance in the encoder circuit and, therefore, movement of the motor shaft and a damper linked thereto.

Abstract: A programmed automatic drill control for optimizing the drilling of subterranean holes by large drilling machinery such as blast hole drills. Sensing means are provided to sense a first set of drilling parameter limits to effect maximum r.p.m. of the motor to rotate the pipe drilling bit and to sense a second set of drilling parameter limits to effect a maximum rate for the motor to drive the hoist pull-down mechanism. These conditions will prevail until a sensed limit is reached or the drilling conditions require operation along a torque or force limit set value. When a limit is reached, the control will regulate at a value of r.p.m. or rate which is consistent with maintaining operation at the limit value.

Abstract: A dual automatic leveling system for a blast hole drill during raising and lowering which includes "fine" level sensors to detect an attitude within a fine level range and "coarse" level sensors to detect an attitude outside a coarse level range which is greater than that of the first. A controller is connected to the sensors as well as to appropriate valving with a pressurized fluid source so as to operate hydraulic jacks. The jacks are activated in a first mode in conjunction with the "fine" sensors and in a second mode in conjunction with the "coarse" sensors. In a preferred manner, the "fine" and "coarse" level sensors are positioned as front, rear, and end level sensors mounted on the main frame of the blast hole drill. The "fine" level sensors in conjunction with a programmable logic control will initially level the drilling platform within a .+-.0.5.degree. (both transverse and longitudinally). If during the raising or lowering process the platform becomes out of level by 2.degree.

Abstract: A substantially constant impedance is developed across the input terminals of a linear amplifier used in a very high frequency (VHF) low band television transmitter. The input circuit consists of lumped components arranged in a capacitively coupled double tuned configuration. A relatively long coaxial transmission line system is used to connect the input circuit to the terminals of the tube. The coaxial line system and input circuit tunes across the entire VHF low band of 54 to 88 MHz. An input voltage standing wave ratio (VSWR) equal to or less than 1.2:1 is achieved over each six MHz channel.