Abstract: An electronically controlled programmable wall thermostat provides better control of comfort temperature and permits improved energy-saving temperature setback at selected intervals of the day or night in multistage heating and cooling systems and is particularly useful in achieving improved energy savings for systems having heat pump means in the main temperature conditioning stage of the system. The thermostat includes clock means, temperature sensing means, means for displaying desired parameters of time and temperature, data entry and storage means for programming the thermostat to maintain desired temperatures during selected time intervals, and a processing means with a memory incorporating a permanently stored program instruction sequence which responds to signals from the temperature sensing means for controlling the heating and cooling systems in accordance with the time-temperature sequence programmed into the thermostat by the user.

Abstract: An electronic digital programmable wall thermostat system for controlling heating and cooling systems supplying an indoor area or space. The thermostat includes a digital clock, a display for displaying desired parameters of time and temperature and a data entry keyboard for programming the thermostat to maintain desired temperatures during selected time intervals. The heart of the system is a digital processor with memory, which responds to signals from a temperature sensing means which includes an analog to digital converter for controlling the heating and cooling systems in accordance with the sequence programmed therein. An output from the processor gates a triac on and off which in turn activates or deactivates the heating and cooling systems. In a preferred embodiment, a single chip digital processor is used to control the operation of the thermostat system, the keyboard, display and temperature sensing means being selectively scanned from output terminals of the digital processor.

Abstract: A vehicle skid control braking system of the type that generates brake control signals varying in accordance with braking conditions, such as vehicle speed, wheel speed and road surface conditions. The system includes: (1) frequency converter apparatus that have pulse generating apparatus responsive to variable frequency wheel speed signals for producing a D.C. signal having a magnitude related to and varying with the frequency of the wheel speed signals; (2) wheel speed rate detector apparatus responsive to the D.C.

Abstract: A vehicle skid control braking system of the type that includes circuit components for generating a signal varying in accordance with braking conditions, such as vehicle speed, wheel speed and road surface conditions. The vehicle skid control braking system includes a ramp generator responsive to the signal generating circuitry, wherein the ramp generator has a charge storage device for storing a charge proportional to the varying signal, control circuitry having an output signal varying between first and second valves, and a discharge circuit for discharging the storage device at a controlled rate to a level determined by the varying of the output signal of the control circuitry from the first value to the second value. The ramp generator produces an output current that varies inversely with vehicle speed.

Abstract: A vehicle skid control braking system including a circuit for generating a signal having a magnitude varying in accordance with braking conditions such as vehicle speed, wheel speed and road surface conditions, a circuit for generating a retarding force signal proportional to such braking control factors and a circuit for generating a ramp signal varying in accordance with vehicle speed, and a speed switch responsive to vehicle wheel speed signals, retarding force signals and velocity ramp signals for producing a speed dependent control signal for controlling the vehicle braking system.

Abstract: An improved vehicle skid control braking system is provided of the type that selectively controls the engagement and disengagement of the brake system of the vehicle in accordance with selective braking conditions, such as vehicle, speed, wheel speed, road surface conditions, wheel speed "slip" conditions, etc.

Abstract: A control circuit having an adaptive turn-off feature for a vehicle skid control braking system, wherein the control circuit is responsible for producing a brake control signal which is effective to disengage the brakes of the vehicle by actuating a brake control valve to a fluid pressure-relieving position. The control circuit features an adaptive turn-off circuit which terminates the brake control signal, thereby enabling re-engagement of the vehicle brakes depending on the coefficient of friction of the road surface being travelled by the vehicle and the degree to which the wheel speed departs from the vehicle speed during the brake disengage cycle of the control circuit. The adaptive turn-off circuit of the control circuit utilizes a wheel departure amplifier which provides an inverted wheel departure signal as determined during a brake disengage cycle of the control circuit, the inverted wheel departure signal being referenced to a zero voltage.

Abstract: An improved vehicle skid control braking system is provided of the type that selectively controls the engagement and disengagement of the brake system of the vehicle in accordance with selective braking conditions, such as, vehicle speed, wheel speed, road surface conditions, wheel speed "slip" conditions, etc.

Abstract: An improved vehicle skid control braking system is provided of the type that selectively controls the engagement and disengagement of the brake system of the vehicle in accordance with selective braking conditions, such as, vehicle speed, wheel speed, road surface conditions, wheel speed "slip" conditions, etc.

Abstract: Provided is a DC level detector and zero velocity gate circuit utilized in a vehicle skid control braking system. The circuit includes a first signal generator for generating a plurality of DC signals when the DC voltage level of a varying DC signal coupled to the circuit reaches a selected value, i.e., a DC voltage level representative of a substantially zero frequency condition. The varying DC signal is preferably proportional to the wheel speed of a moving vehicle. The circuit also includes a second signal generator for generating a gate signal indicating when the DC level reaches a selected level which indicates a zero velocity wheel speed. The first signal generator generates first and second signals which are differentiated by third and fourth signal generators indicating vehicle deceleration and vehicle acceleration in the vehicle skid control braking system.

Abstract: A vehicle skid control braking system is provided of the type that selectively controls the engagement and disengagement of the brake system of the vehicle in accordance with selective braking conditions, such as, vehicle speed, wheel speed, road surface conditions, wheel speed "slip" conditions, etc.

Abstract: An anti-skid control system for vehicle brakes which is much simpler and of lower cost than prior art systems and yet provides substantially the same anti-skid brake control. The system includes a frequency-voltage converter to produce a voltage signal indicative of wheel speed which is utilized as an input to a deceleration rate detector and an acceleration differentiator connected in parallel. The acceleration differentiator provides control signals to the deceleration rate detector to set threshold values therefor. When both the deceleration rate detector and the acceleration differentiator produce output signals of proper type to an AND gate, the system deactivates the normal braking system for the vehicle to avoid a potential skid condition. The system includes an override for applying brakes when an acceleration exceeds a predetermined threshold value.