公开(公告)号：US09018962B2

公开(公告)日：2015-04-28

申请号：US13736927

申请日：2013-01-08

申请人： Gary R. Hoffman ,  Edward S. Kwon ,  Hong Cai

发明人： Gary R. Hoffman ,  Edward S. Kwon ,  Hong Cai

IPC分类号： G01R31/06 ,  G01R31/02 ,  G01R31/12 ,  H02H7/04 ,  H02H3/093 ,  H02H3/52

CPC分类号： G01R31/027 ,  G01R31/1227 ,  H02H3/093 ,  H02H3/52 ,  H02H5/005 ,  H02H7/04 ,  H02H7/0455

摘要： A protective system far a power transformer having a neutral line connected to ground where large currents can flow in the neutral line due to electro-magnetic disturbances. The system includes circuitry for: (a) sensing the current level in the neutral line and whether it exceeds a predetermined threshold for a predetermined period; and (b) sensing and processing the harmonic content of the load current and determining the existence of certain relationships of the “even” and “odd” harmonics. Signals, including alarms, indicative of excessive conditions are produced. The system may also include circuitry for sensing the load current level and generating a signal alarm if the load level is above a given value when the harmonics and the DC current have values in excess of certain predetermined values.

摘要翻译： 远离电力变压器的保护系统，其中性线连接到地面，由于电磁干扰，大电流可能在中性线中流动。 该系统包括用于以下步骤的电路：（a）感测中性线中的电流电平以及它是否在预定时间段内超过预定阈值; 和（b）感测和处理负载电流的谐波含量并确定“偶数”和“奇数”谐波的某些关系的存在。 产生指示过度状况的信号，包括报警。 如果谐波和DC电流的值超过某些预定值，则系统还可以包括用于感测负载电流电平和产生信号报警的电路，如果负载电平高于给定值。

公开(公告)号：US08274769B2

公开(公告)日：2012-09-25

申请号：US12802412

申请日：2010-06-07

申请人： Gary R. Hoffman ,  Jeffrey Anderson

发明人： Gary R. Hoffman ,  Jeffrey Anderson

IPC分类号： H02H7/04 ,  H02H5/06 ,  H01F27/10 ,  H01F27/12

CPC分类号： H01F27/402 ,  H01F2027/406

摘要： The cooling system for a power transformer is activated by sensing and processing the frequency characteristic including the harmonic contents, of the inrush current into the transformer, when the transformer is first energized. The cooling system may include motors operating devices such as oil circulating pumps and fans causing a coolant to flow about the power transformer. The cooling system is deactivated by sensing when the transformer is de-energized and when its temperature is below a predetermined level.

摘要翻译： 当变压器第一次通电时，通过检测和处理包括谐波含量的入侵变压器的浪涌电流的频率特性来激活电力变压器的冷却系统。 冷却系统可以包括马达操作装置，例如油循环泵和风扇，使得冷却剂在电力变压器周围流动。 当变压器断电并且当其温度低于预定水平时，冷却系统被去激活。

公开(公告)号：US4532501A

公开(公告)日：1985-07-30

申请号：US345193

申请日：1982-02-02

申请人： Gary R. Hoffman

发明人： Gary R. Hoffman

IPC分类号： F16P3/14 ,  G01V3/08 ,  G08B21/00

CPC分类号： G01V3/088 ,  F16P3/14 ,  F16P3/148

摘要： A safety system for a machine tool is characterized by a capacitively coupled electric field generator (transmitter) and a capacitive receptor antenna. An electrical signal is induced in the capacitive receptor antenna by the action of the electric field. The magnitude of the induced signal is monotonically related to the distance between the electric field generator and the capacitive receptor antenna. When the magnitude of the electrical signal exceeds a predetermined threshold, a machine tool safety indicator is developed.

摘要翻译： 用于机床的安全系统的特征在于电容耦合电场发生器（发射器）和电容式接收器天线。 通过电场的作用在电容式接收天线中感应出电信号。 感应信号的幅度与电场发生器和电容式接收天线之间的距离单调相关。 当电信号的大小超过预定阈值时，开发出机床安全指示器。

公开(公告)号：US08260472B2

公开(公告)日：2012-09-04

申请号：US12381184

申请日：2009-03-09

申请人： Gary R. Hoffman ,  Jeffrey Anderson

发明人： Gary R. Hoffman ,  Jeffrey Anderson

IPC分类号： G06F19/00

CPC分类号： H01F27/085 ,  H01F2027/404

摘要： A system for cooling a power transformer which generates heat, when driving a load, includes cooling devices, such as fans and pumps, located about the transformer, which are powered for circulating a coolant about the transformer. Each cooling device has a motor which is energized in response to given temperature (heat) conditions. In systems embodying the invention, the currents flowing through the motors of cooling devices are sensed and monitored to determine whether the cooling devices are functioning correctly and to substitute functional cooling devices for those which are malfunctioning. Sensing the currents in the motors enables the early detection of fault conditions in the cooling system. It also enables the monitoring of operating conditions and running time of the cooling devices to aid in the maintenance and operation of the cooling system.

摘要翻译： 用于冷却在驱动负载时产生热量的电力变压器的系统包括围绕变压器的冷却装置，例如风扇和泵，其用于使变冷器周围的冷却剂循环。 每个冷却装置具有响应于给定温度（热）条件而通电的马达。 在体现本发明的系统中，感测和监测流过冷却装置的电动机的电流，以确定冷却装置是否正常工作，并将功能冷却装置替换为故障的冷却装置。 感测电机中的电流可以早期检测冷却系统中的故障状况。 它还能够监测冷却装置的运行状况和运行时间，以帮助冷却系统的维护和运行。

公开(公告)号：US20100315188A1

公开(公告)日：2010-12-16

申请号：US12802412

申请日：2010-06-07

申请人： Gary R. Hoffman ,  Jeffrey Anderson

发明人： Gary R. Hoffman ,  Jeffrey Anderson

IPC分类号： H01F27/10

CPC分类号： H01F27/402 ,  H01F2027/406

摘要： The cooling system for a power transformer is activated by sensing and processing the frequency characteristic including the harmonic contents, of the inrush current into the transformer, when the transformer is first energized. The cooling system may include motors operating devices such as oil circulating pumps and fans causing a coolant to flow about the power transformer. The cooling system is deactivated by sensing when the transformer is de-energized and when its temperature is below a predetermined level.

摘要翻译： 当变压器第一次通电时，通过检测和处理包括谐波含量的入侵变压器的浪涌电流的频率特性来激活电力变压器的冷却系统。 冷却系统可以包括马达操作装置，例如油循环泵和风扇，使得冷却剂在电力变压器周围流动。 当变压器断电并且当其温度低于预定水平时，冷却系统被去激活。

公开(公告)号：US06459998B1

公开(公告)日：2002-10-01

申请号：US09619516

申请日：2000-07-19

申请人： Gary R. Hoffman

发明人： Gary R. Hoffman

IPC分类号： H02H300

CPC分类号： H02H1/0076 ,  H02H5/10

摘要： In systems embodying the invention, a “downed” power line is detected by sensing whether there is an open circuit along the power line and producing an indication that an open circuit condition exists. In response to an indication that an open circuit condition exists, the system compares the nature of the voltage and/or current signals present on the power line at the time an open circuit condition is indicated to exist, with a preprogrammed stored condition which includes typical signals to be expected when a “break” occurs along a power line. When a downed power line is detected, power is then removed from the affected line.

摘要翻译： 在体现本发明的系统中，通过检测沿着电力线路是否存在开路并产生存在开路状态的指示来检测“降频”电力线。 响应于存在开路状况的指示，系统将比较存在于开路条件下存在的电力线上存在的电压和/或电流信号的性质与预编程的存储条件，其包括典型的 沿着电力线发生“断裂”时预期的信号。 当检测到欠电压电源线时，电源从受影响的线路中移除。

公开(公告)号：US4939617A

公开(公告)日：1990-07-03

申请号：US349330

申请日：1989-05-05

申请人： Gary R. Hoffman ,  Walter L. Hinman

发明人： Gary R. Hoffman ,  Walter L. Hinman

IPC分类号： H02H3/00 ,  H02H3/28 ,  H02H7/26

CPC分类号： H02H7/263

摘要： The invention is directed to an improved method and apparatus for monitoring the status of an AC electrical transmission line connected between first and second locations. In a disclosed embodiment of the method of the invention, first signal parameter values are generated, for the first location, by time integrating between zero-crossings of an AC signal parameter measured at the first location. Second signal parameter values are generated, for the second location, by time integrating between zero-crossings of the AC signal parameter measured at the second location. The second signal parameter values are transmitted to the first location. In a form of this embodiment, the second signal parameter values transmitted for each of the three phases are transmitted only for time periods between successive zero-crossings beginning with a zero-crossing of one sense (e.g. positive-going zero-crossings), and the second signal parameter value for the ground reference return is transmitted only for time periods between successive zero-crossings beginning with a zero-crossing of an opposite sense (e.g. negative-going zero-crossings) to said one sense. This technique can provide a further saving of bandwidth without substantial compromise of tripping response time.

摘要翻译： 本发明涉及一种用于监测连接在第一和第二位置之间的交流输电线的状态的改进的方法和装置。 在本发明方法的公开实施例中，通过在第一位置处测量的AC信号参数的过零点之间的时间积分，为第一位置产生第一信号参数值。 对于第二位置，通过在第二位置处测量的AC信号参数的过零点之间的时间积分来生成第二信号参数值。 第二信号参数值被发送到第一位置。 以本实施例的形式，对于三个相位中的每一个发送的第二信号参数值仅在从一个感测（例如，正向过零点）的零交叉开始的连续过零点之间的时间段内传送，以及 接地参考返回的第二信号参数值仅在连续的过零点之间的时间段被发送，从与所述一个方向相反的意义（例如负向过零点）的过零点开始。 该技术可以进一步节省带宽，而不会大大损害跳闸响应时间。

公开(公告)号：US4608564A

公开(公告)日：1986-08-26

申请号：US439921

申请日：1982-11-08

申请人： Gary R. Hoffman

发明人： Gary R. Hoffman

IPC分类号： G01R11/16

CPC分类号： G01R11/16

摘要： An improved pick-up means for the remote monitoring of a rotating shaft, or a wheel mounted on the shaft, utilizes the inductive coupling effect between an aperture formed in an annular conductive member and at least one pair of coils or inductors fixedly mounted radially of the annular member. As applied to the remote monitoring of a standard electric service meter, the annular member comprises a metallic rim on the circumference of a plastic disc mounted on a shaft which is journaled within the top front panel of the meter, concentrically within the unit decade dial. Preferably, three inductors are employed, including first and second inductors and a third common inductor therebetween, thereby forming two pairs of inductors; and the signal is generated in the third common inductor whenever a respective aperture on the rim of the disc circumferentially bridges a respective pair of inductors at a predetermined position of the disc.

摘要翻译： 用于远程监测旋转轴或安装在轴上的轮的改进的拾取装置利用形成在环形导电构件中的孔与至少一对线圈或电感器之间的感应耦合效应，固定地安装在 环形构件。 如应用于标准电气服务仪表的远程监控，环形构件包括在安装在轴上的塑料盘的圆周上的金属边缘，其轴向位于仪表的顶部前面板内，同心地位于单元十分表内。 优选地，使用三个电感器，包括第一和第二电感器以及它们之间的第三公共电感器，由此形成两对电感器; 并且只要盘的边缘上的相应孔在盘的预定位置周向地桥接相应的一对电感器，则在第三公共电感器中产生信号。

公开(公告)号：US20090315657A1

公开(公告)日：2009-12-24

申请号：US12381184

申请日：2009-03-09

申请人： Gary R. Hoffman ,  Jeffrey Anderson

发明人： Gary R. Hoffman ,  Jeffrey Anderson

IPC分类号： H01F27/10 ,  H01F27/02

CPC分类号： H01F27/085 ,  H01F2027/404

摘要： A system for cooling a power transformer which generates heat, when driving a load, includes cooling devices located about the transformer which are powered to remove excessive heat from the transformer. The cooling devices may include fans to blow air onto the transformer and pumps for circulating a coolant about the transformer. The cooling devices of interest have a motor (e.g., a fan motor or a pump motor) which is energized in response to given temperature (heat) conditions. In systems embodying the invention, the currents flowing through the motors of cooling devices are sensed and monitored to determine whether the cooling devices are functioning correctly and to substitute functional cooling devices for those which are malfunctioning. The importance of sensing the motor currents and substituting operational cooling devices for defective ones is that a temperature rise due to a failure of a cooling device is not immediately detectable due to the large thermal constants associated with the transformer assembly. Sensing the currents in the motors enables the early detection of fault conditions in the cooling system. It also enables the monitoring of operating conditions and running time of the cooling devices to aid in the maintenance and operation of the cooling system.

摘要翻译： 用于冷却在驱动负载时产生热量的电力变压器的系统包括位于变压器周围的冷却装置，其被驱动以从变压器去除过多的热量。 冷却装置可以包括将空气吹到变压器上的风扇和用于在变压器周围循环冷却剂的泵。 感兴趣的冷却装置具有响应于给定温度（热）条件而被激励的电动机（例如，风扇电动机或泵电动机）。 在体现本发明的系统中，感测和监测流过冷却装置的电动机的电流，以确定冷却装置是否正常工作，并将功能冷却装置替换为故障的冷却装置。 检测电动机电流和替代运行冷却装置的重要性是由于与变压器组件相关联的大的热常数，由于冷却装置的故障导致的温度上升不能立即被检测到。 感测电机中的电流可以早期检测冷却系统中的故障状况。 它还能够监测冷却装置的运行状况和运行时间，以帮助冷却系统的维护和运行。

公开(公告)号：US4608563A

公开(公告)日：1986-08-26

申请号：US374626

申请日：1982-05-03

申请人： Gary R. Hoffman

发明人： Gary R. Hoffman

IPC分类号： G01R11/16 ,  G01R21/133 ,  G06M1/274 ,  G08B23/00

CPC分类号： G01R21/133 ,  G01R11/16 ,  G06M1/274

摘要： A wheel is mounted on a rotating shaft and cooperates with at least one pair of inductors fixedly mounted in juxtaposition to the wheel. The wheel has at least one opening formed therein for generating a signal whenever the opening in the wheel is substantially aligned circumferentially with the pair of inductors. An electronic control circuit, responsive to the signal, actuates a remote meter for providing a remote indication of the shaft position.In a preferred embodiment, this improved sensing means is applied to the remote reading of a conventional household electric meter. Two pair of inductors are provided for cooperation with five equiangularly-spaced closed slots formed in the wheel, thereby providing ten signals (or counts) for each complete revolution of the wheel. The wheel is mounted on the shaft of the unit decade dial in the meter. The remote meter comprises a digital counter, responsive to the pulse generated by the electronic control circuit, for providing a remote digital read-out of the accumulated kilowatt hours on the meter.

摘要翻译： 车轮安装在旋转轴上，并与至少一对固定安装在车轮上的电感器配合。 车轮上至少有一个开口形成在其中，用于当车轮中的开口基本上与该对电感器对齐时产生信号。 响应于该信号的电子控制电路致动远程仪表以提供轴位置的远程指示。 在优选实施例中，这种改进的感测装置被应用于传统家用电表的远程读取。 提供两对电感器用于与车轮中形成的五个等角度间隔的闭合槽配合，从而为车轮的每次完整转动提供十个信号（或计数）。 车轮安装在仪表的单位十年表盘的轴上。 远程仪表包括数字计数器，响应于由电子控制电路产生的脉冲，用于在仪表上提供累积千瓦小时的远程数字读出。