摘要:
A load driving device according to an aspect of the present invention may includes an output transistor and a load connected in series between first and second power supply lines, a protection transistor connected between a gate of the output transistor and the second power supply line, the protection transistor turning on the output transistor when a polarity of a power supply connected between the first and second power supply lines is reversed, and a resistor arranged on a line, which supplies a voltage to a back gate of the protection transistor.
摘要:
The life of load tap changer contacts is monitored by detecting an arcing event; identifying arcing surfaces involved in the arcing event; calculating a per-unit loss of life for the identified arcing surfaces as a result of the arcing event; updating estimates of cumulative erosion for the arcing surfaces; comparing the updated estimates of cumulative erosion to a first threshold value; and signaling for action when at least one of the updated estimates of cumulative erosion exceeds the first threshold value.
摘要:
A distributed airbag firing system (10) includes a controller (12) receiving sensor signals from a sensor (20) over a two-wire bus (18). The controller provides a firing command over to the two-wire bus to a squib driver circuit (26), which provides the firing current necessary to detonate a squib device (32) and inflate the airbag. The squib driver circuit includes a rectifier (42) with its first and second inputs interchangeably connected to the two-wire bus. The rectifier circuit converts the voltage orientation on the first and second conductors to a positive potential on a first output conductor and a negative or ground potential on a second output conductor. The interchangeability of the first and second inputs of the rectifier to the two-wire bus makes the connection arbitrary and fail-safe.
摘要:
A plurality of air conditioning system control units are connected to each other through a communication line (20). Discharge resistors (R1, R2) are provided for discharging residual charges of the communication line (20). The control unit has a power superposition circuit (50) for applying a direct-current voltage and outputs an identification number signal from the power superposition circuit (50) to the communication line (20). The control unit further has a polarity select circuit (60) having a negative-polarity resistance characteristic that current increasingly flows as an applied voltage is lowered, and a voltage discriminating circuit (70) for detecting the terminal voltage of the polarity select circuit (60). When detecting the voltage of the communication line (20), the control unit determines whether its own control unit is a master unit or a slave unit according to output signals from the voltage discriminating circuit (70) and a polarity discriminating circuit (3C).
摘要:
For appropriately polarity recognition and corresponding switchover of a output stage of a proximity switch or the like connected to a supply voltage (VB), even while continuously activated, when a change in load polarity occurs, the proximity switch having in each case a high side driver and a low side driver, it is proposed to define on the output-side voltage axis between the positive supply voltage (+VB) and the negative pole or ground an upper and a lower detection window which sense the load configuration, each at a distance from the working points (which remain in a steady state) of each output stage driver, such that when a change in load configuration occurs, the potential of the output connection, to which the load configuration detection stage is connected, passes only briefly through these detection windows, and such that the transient signal changes which result therefrom in each window region are used for appropriately polarized switchover to the respective correct output stage circuit section based on a switchover of the load configuration detection stage.
摘要:
A multiphase contactor with solid state circuity gating rectified pulses to an electromagnetic coil to close and hold closed contacts for each phase, sequentially for each successive opening of the contactor adjusts the delay angle of the last pulse to rotate the sequence in which the individual phase currents are interrupted. By alternately making the last pulse positive or negative the polarity of the interrupted current alternates to further promote even contact wear.
摘要:
A pulse generator for reversing a d.c. supply at 10 cycles per second for a telephone control circuit uses a relay operated by a transistor either directly or by means of an additional transistor. A timing capacitor is connected to the base of the transistor and the other terminal of the capacitor is switched to ground by the relay after the transistor turns off, and is switched to a charging resistor connected to the power supply after the transistor turns on. When the capacitor is grounded, other contacts of the relay provide a charging path from the power supply through a resistor to the ungrounded side of the capacitor. The first-mentioned charging resistor may be connected to the power supply through R-C filtering. When an additional transistor is used which is of the complementary type relative to the timing transistor, the circuit''s tolerance of power supply ripple can be improved by the addition of feedback through a diode.