摘要:
A self-optimizing energy harvester comprises a thermoelectric generator coupling to a thermal source, producing a source voltage greater than a minimum start-up voltage, where the thermoelectric generator drives a boost circuit and a feedforward circuit, delivering power to a load. A conventional boost circuit has a maximum output power only at the input voltage for which a fixed set point resistor is chosen. The feedforward circuit dynamically optimizes the boost circuit according to a dynamic set point resistance, thus increasing output power for a wide range of input voltages, relative to using a fixed reference resistor. The dynamic set point resistance is the sum of a variable resistance and a reference resistance. A sample element forms a differential voltage between the source and input voltage elements, and the variable resistance corresponds to the differential voltage. A reference resistor is chosen to establish the minimum start-up voltage.
摘要:
A method of controlling a blower motor in a furnace includes applying control signals to the blower motor; determining that a reference airflow through a portion of the furnace is present; determining a reference control signal at which the reference air flow is present; receiving a requested airflow; computing a requested control signal in response to the reference air flow, the reference control signal and the requested airflow; and using the requested control signal to control the blower motor.
摘要:
In a modulating furnace with an integrated furnace control (IFC) that may enter a lockout mode for any one or more of a variety of safety reasons, the IFC may be programmed to send a “home” signal to the regulator stepper motor to close the regulator seat thereby reducing the outlet pressure of the gas valve to zero or near zero. Even though the ITC may have several different safety lockout modes, an additional home command from the IFC allows the modulating gas valve to position itself to a reference point such that the outlet pressure would approach zero pressure, even when the gas valve is energized at the wrong time due to a short circuit or miswire, or mechanically stuck open. By using the home command, an additional safety redundancy is provided whenever the furnace enters a lockout mode.
摘要:
A method for adjusting the continuous speed of the blower of a heating and/or cooling system of the type including a thermostat having a mode selector switch which has at least one heating position, a cooling position, and an off position, a fan switch having an on position or state and an auto position or state, and a programmable control device responsive to the thermostat for generating speed select signals for use in setting the speed of the blower motor. The programmable control device is programmed or reprogrammed so that, when the mode selector switch is in its off position or when there is no call for heating or cooling at the thermostat, time dependent movements of the fan switch away from and back to its on position are recognized as requests for changes in the continuous speed of the blower motor. The programmable control device is further programmed or reprogrammed to change the blower speed from one value to the next adjacent value each time the programmable control device recognizes the occurrence of a request for a change in speed.
摘要:
A method for providing a low fire mode and a high fire mode of a heating cycle in a current cycle of a furnace as a function of the previous heating cycle wherein the current heating cycle is a function exclusively of time run in low fire mode and time run in high fire mode of the previous heating cycle, comprising the steps of: (1) determining the existence of a heating load to be satisfied; (2) running burners in low fire mode for a first time interval that does not exceed a predetermined limit, L.sub.des ; (3) running the burners in high fire mode for a second time interval until the heating load is satisfied; (4) calculating a BtU load requirement, as a function of the first time interval and the second time interval; and (5) determining the desired low fire mode time limit, L.sub.des, for the next cycle from the calculated BtU load requirement.
摘要:
In a fixed-firing rate induced draft furnace, having a heat exchanger and an integrated control inducer motor, an improved method of controlling excess air comprising the steps of: providing at least one pressure switch that is responsive to a preselected pressure drop level in the heat exchanger, the pressure drop level being selected so as to be commensurate with a theoretically desired excess air level under firing operating conditions; accelerating the integrated control inducer motor until the pressure switch closes and thereupon recording a first motor speed and a first current level; calculating a first torque value based on the first motor speed and the first current level; and regulating torque applied to the integrated control inducer motor in accordance with the first torque value.
摘要:
The power output of a variable speed motor is limited to a safe level by determining the maximum allowable speed corresponding to a maximum power output limit over a range of load conditions and then maintaining the speed of the motor below those maximum allowable speeds at the particular load conditions existing at the time.
摘要:
An adaptive motor control for a furnace with or without an evaporator coil determines and delivers the desired CFM for each thermostat cycle. Specifically, a circulating air blower driven by an ECM is initially set at a known duty cycle for each thermostat cycle and the delivered CFM is calculated. The RPM necessary to deliver the desired CFM is then determined and the ECM is set accordingly.
摘要:
A furnace includes an induced draft blower; an inducer motor driving the induced draft blower; and a furnace control determining a modulation percentage, the furnace control controlling RPM of the inducer motor in response to the modulation percentage.
摘要:
A pressure switch assembly is used with a furnace controller having a first input and a second input. A first pressure switch is configured to actuate at a first combustion pressure level and is connected to the first input. A second pressure switch is configured to actuate at a second combustion pressure level, and a third pressure switch is configured to actuate at a third combustion pressure level. Pressure signals provided on the second input from at least one of the second pressure switch and the third pressure switch are used by the furnace controller to derive actuation states of the second and third pressure switches.