公开(公告)号：US06972921B1

公开(公告)日：2005-12-06

申请号：US10818327

申请日：2004-04-05

Applicant: Sakti Rana ,  Yayue Zhang ,  Siew Yong Chui

Inventor： Sakti Rana ,  Yayue Zhang ,  Siew Yong Chui

IPC: G11B21/02 ,  G11B21/12 ,  H02J7/04 ,  H02M3/07

CPC classification number: H02M3/07 ,  G11B21/12 ,  H02M1/36

Abstract: A circuit and method protects an emergency head-retract capacitor that regulates initial charge current using a constant current source. The initial charge current is applied at power-up to the capacitor until a charging voltage having a desired threshold level is attained in the capacitor. The charging voltage is monitored through an analog-to-digital converter by an overall controller that, upon detecting the presence of the desired threshold level in the capacitor, deenergizes the constant current source. A voltage pump, which includes a voltage multiplier (doubler), is then activated to selectively apply regulated charging voltage to thereafter maintain the desired threshold level. The pump includes a voltage pump controller that is controlled by a voltage comparator having a reference voltage set to a desired threshold level. That voltage comparator is also in communication with the capacitor to measure its present input charging voltage. When the desired threshold level is met or exceeded at the capacitor, the comparator signals the controller to deactivate the pump. When the capacitor's charging voltage is less than the reference voltage, the comparator signals the controller to activate the voltage pump and, thus, pump the capacitor with regulated voltage.

Abstract translation: 电路和方法保护使用恒定电流源来调节初始充电电流的紧急头退电容器。 在电容器上电时施加初始充电电流，直到在电容器中获得具有期望阈值电平的充电电压。 通过总体控制器通过模拟 - 数字转换器来监测充电电压，其在检测到电容器中存在期望的阈值电平时，使恒定电流源失电。 然后激活包括电压倍增器（倍增器）的电压泵，以选择性地施加调节的充电电压，此后保持期望的阈值电平。 泵包括电压泵控制器，其由具有设置为期望阈值水平的参考电压的电压比较器控制。 该电压比较器也与电容器通信，以测量其当前的输入充电电压。 当电容器满足或超过所需的阈值电平时，比较器发出信号通知控制器停用泵。 当电容器的充电电压小于参考电压时，比较器通知控制器激活电压泵，从而以调节电压对电容器进行泵浦。