发明名称 |
PWM driver for an inductive load with detector of a not regulating PWM condition |
摘要 |
A pulse width modulated (PWM) transistor driver circuit, for driving an inductive load, has a load-current sensing resistor and a comparator having an input connected to the sensing resistor and another input to which a PWM control reference voltage may be applied. A PWM driver-control circuit includes a set-dominant PWM latch, and a not-regulating detector that may be composed entirely of logic circuit blocks or a combination of logic and analog circuits. By either means, the PWM bridge-control circuit includes a timer for repeatedly generating control pulses that set and hold a PWM latch beginning each PWM period, and the comparator resets the latch each time after the timer pulse the load current rises to exceed a corresponding reference voltage level. A sample-time-interval is defined beginning at the time of termination of a control pulse and a not-regulating pulse generator produces a not-regulating pulse only during the sample-time when the load current exceeds the level of the applied reference signal, indicating that the PWM system is failing to regulate the load current. Further, the not-reg pulse width is, under most load conditions and over a wide range of applied reference voltage levels, a measure of the degree of failure of the PWM driver to regulate.
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申请公布号 |
US5757214(A) |
申请公布日期 |
1998.05.26 |
申请号 |
US19960647851 |
申请日期 |
1996.05.15 |
申请人 |
STODDARD, ROBERT J.;PEPPIETTE, ROGER C. |
发明人 |
STODDARD, ROBERT J.;PEPPIETTE, ROGER C. |
分类号 |
H01H47/32;H02H7/08;(IPC1-7):H03K17/16;H03K3/01 |
主分类号 |
H01H47/32 |
代理机构 |
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主权项 |
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地址 |
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