초록 ▼

A forced air gas heating furnace system includes a thermostat having a transformer for converting the typical household 115Vac to a 24V thermostat ac control voltage, and a switch, the thermostat elements connected to the junction of an ac to dc converter, a digital control circuit and a TRIAC. The

A forced air gas heating furnace system includes a thermostat having a transformer for converting the typical household 115Vac to a 24V thermostat ac control voltage, and a switch, the thermostat elements connected to the junction of an ac to dc converter, a digital control circuit and a TRIAC. The dc output is connected to a dc voltage regulator which outputs Vcc for a digital control circuit. The gate of the TRIAC is connected to the output of the digital control circuit, and operates in response thereto for selectively triggering the TRIAC for passing the 24Vac transformer control power to a solenoid operated gas valve. The solenoid gas valve is connected between the gas source and the gas burner to control the gas supply to the burner in response to the digital control circuit signal operation of the TRIAC; first on to heat the furnace heat exchanger to an operating temperature, and thereafter off and on for selected periods necessary to maintain the operating temperature of the heat exchanger while conserving gas. The control circuit includes a square wave generator for converting the thermostat 60 Hz 24Vac to square waves for a counter/divider. The counter/divider generates pulses suitable for counters of a dual binary counter counting the pulses for outputting selected timing control signals to a logic circuit (plurality of NOR gates). The logic circuit outputs high/low state signals to a TRIAC driver (opto-coupler) which drives the TRIAC in response to the high/low state output of the logic circuit for controlled operation of the gas furnace.

대표청구항 ▼

A control device for a system such as a forced air gas burning central heating system or the like comprising: a. power means for producing ac voltage for operation of the system and converting ac power to dc power for a control means; b. gate controlled semiconductor switch means connected to the po

A control device for a system such as a forced air gas burning central heating system or the like comprising: a. power means for producing ac voltage for operation of the system and converting ac power to dc power for a control means; b. gate controlled semiconductor switch means connected to the power means for controlling the connection of ac power to a load; and c. control means connected to the power means for receiving the dc power, and to the gate controlled semiconductor switch for controlling the operation of the switch means in response to the dc power, said control means including first timing means for producing an initial timing signal for the gate controlled semiconductor switch means to conduct ac power for a first preselected time, and a second timing means for producing alternately first and second timing signals for the gate controlled semiconductor switch after the initial signal to block the flow of ac power to the system for a preselected time, and to conduct ac power to the system for a preselected time, wherein the control means further includes a square wave generator connected to the ac power source for producing a plurality of square wave signals at the frequency of the ac source of power, a frequency divider connected to the square wave generator for producing square wave signals having a preselected frequency, the first timing means connected to the frequency divider for generating the initial timing signal for said first preselected time, and the second timing means includes a frequency counter means connected to the frequency divider for thereafter alternately generating said first timing signals for said preselected time periods and said second timing signals for said preselected time periods for the gate controlled semiconductor switch means. A control device for regulating the combustion of gas in a central heating system powered by an ac power source operating through a switch, comprising: square-wave generator means connected to the ac power source for producing a plurality of square wave signals at the frequency of the ac source of power; frequency counter/divider means for driving the power frequency into suitable clocking pulses for determining preselected timing signals; decode counter/divider means connected to the frequency/divider for outputting a plurality of time period indicating signals; and transistor means connected to the decode counter/divider for outputting timing signals to the switch, first to conduct ac power for a preselected time, and thereafter, alternately to block the working ac power for a first preselected time, and to conduct ac power for a second preselected time.