公开(公告)号：US5530615A

公开(公告)日：1996-06-25

申请号：US163782

申请日：1993-12-06

申请人： Mark E. Miller ,  Mark A. Eifler ,  Alan R. Sawyers ,  Mitchell R. Rowlette ,  Craig M. Nold

发明人： Mark E. Miller ,  Mark A. Eifler ,  Alan R. Sawyers ,  Mitchell R. Rowlette ,  Craig M. Nold

IPC分类号： H01H9/56 ,  H01H47/00 ,  H02H3/033

CPC分类号： H01H9/56 ,  H01H2009/566 ,  Y10T307/951

摘要： An electronic control for gas furnaces controls a two speed main blower fan and an induction draft fan based on 24 volt input signals from a room thermostat, a high limit and an ignition control including a gas valve. The input signals are coupled to input ports of a microprocessor through current limiting resistors and to AC ground through pull down resistors. AC ground is also connected to the IRQ port of the microprocessor. Output ports of the microprocessor are connected to a relay driver which in turn is connected to relays for energizing and de-energizing the fans. The control calibrates itself on a continuing periodic basis to read the AC inputs synchronously at the peak of their wave and can switch the relays asynchronously based on the Real Time Clock of the microprocessor or can be switched synchronously by providing a selected delay so that contact engagement and disengagement occurs at or near the zero crossing of the AC line voltage wave form. When used with resistive loads the relays are switch in response to a signal from the microprocessor which is delayed based on the mechanical switching time constant of the relays to provide contact closure and opening at the selected point on the AC line voltage wave form. An alternate embodiment shows a feedback network used to calibrate the specific delay period for each relay upon initialization. When used with inductive loads contact closing can be effected synchronously and contact opening asynchronously.

摘要翻译： 燃气炉的电子控制器基于来自室温恒温器，上限和包括气阀的点火控制器的24伏输入信号来控制双速主鼓风机和引风机。 输入信号通过限流电阻耦合到微处理器的输入端口，并通过下拉电阻耦合到交流电源。 交流接地也连接到微处理器的IRQ端口。 微处理器的输出端口连接到继电器驱动器，继电器驱动器又连接到继电器，以使风扇通电和断电。 控制器在持续的周期性基础上自行校准，以在其波峰值同步读取AC输入，并且可以基于微处理器的实时时钟异步地切换继电器，或者可以通过提供所选择的延迟来同步地切换继电器，使得接触接合 并且在AC线电压波形的过零点处或附近发生分离。 当与电阻性负载一起使用时，继电器响应于来自微处理器的信号而被切换，该信号基于继电器的机械开关时间常数被延迟，以在交流线路电压波形上的选定点处提供触点闭合和断开。 替代实施例示出了用于在初始化时校准每个继电器的特定延迟周期的反馈网络。 当与感性负载一起使用时，触点闭合可以同步进行并且异步接触。