摘要:
A battery charger for charging a battery pack having a battery, a temperature sensor for sensing a temperature of the battery, and a battery terminal. The battery charger includes a charger terminal to which the battery terminal is connected when the battery is charged, a charge current generating circuit that generates a charge current for charging the battery, a battery temperature detector, and a controller. The battery temperature detector is configured to include a circuit, for example, to detect a temperature of the battery while cooperating with the temperature sensor and to output a temperature signal indicative of the temperature of the battery. The controller which is supplied with the temperature signal from the battery temperature detector, corrects the temperature signal, and provides a corrected temperature signal.
摘要:
A DC power source unit supplies a DC voltage to a power tool through an adapter when a power switch of the tool is turned ON and also charges a battery pack used as an alternative power source of the tool when the power tool is not operated. In order to prevent a rush current from flowing in a switch interposed between a switching power source circuit and the battery pack when charging the battery pack is commenced, the switch is rendered OFF when the output voltage from the switching power source is greater than the battery voltage. Charging the battery is started upon once lowering the output of the switching power source to a level lower than the battery voltage.
摘要:
A DC power source unit supplies a DC voltage to a power tool through an adapter when a power switch of the tool is turned ON and also charges a battery pack used as an alternative power source of the tool when the power tool is not operated. A minimum battery temperature gradient amongst battery temperature gradients ever computed is used to determine whether the battery pack has cooling effect when forcibly cooled by a cooling fan or whether the battery pack has reached a full charge condition. When charging the battery pack is interrupted due to operation of the power tool, computing the battery temperature gradient is halted for some time or determination of the battery pack's full charge condition is not performed for some time in order to prevent the minimum battery temperature from being updated during interruption of charging of the battery pack.
摘要:
A DC power source unit supplies a DC voltage to a power tool through an adapter when a power switch of the tool is turned ON and also charges a battery pack used as an alternative power source of the tool when the power tool is not operated. In order to prevent a rush current from flow in a switch interposed between a switching power source circuit and the battery pack when charging the battery pack is commenced, the switch is rendered OFF when the output voltage from the switching power source is greater than the battery voltage. Charging the battery is started upon once lowering the output of the switching power source to a level lower than the battery voltage.
摘要:
A full charge condition of a battery is determined based on a battery temperature gradient computed at every sampling time based on two values of detected battery temperatures. However, the battery temperature detected when the level of a charge current is switched does not exhibit an accurate temperature of the battery due to contact resistance existing in contact portion of a battery side terminal and a charger side terminal, resulting in inaccurate detection of the full charge condition. A microcomputer corrects the battery temperatures detected after the level of the charge current is switched and the full charge determination is made through computation of the battery temperature gradient using the corrected battery temperatures.
摘要:
To provide a battery charger capable of fully charging both an active battery and an inactive battery, which have different charging characteristics near the peak level, a voltage across the battery is periodically sampled during charging the battery. A voltage change is obtained by subtracting a voltage that has been sampled previously from the newly sampled voltage. Determination of the fully charged condition of the battery is made when a voltage change falls below a critical value (S1, S2) after identifying that the battery being charged is an active or inactive battery using another critical values (K1, K2 or K1′, K2′). The critical values S1 and S2 and another critical values K1 and K2 (or K1′ and K2′) are selectively referred to depending to the battery voltage change.
摘要:
A digital miter saw for cutting a workpiece includes a base, a member supported on the base and moveable relative to the base, and a cutting member moveable with the member. A detector is provided for detecting at least one of a miter angle and a bevel angle between the cutting member and the workpiece, and for outputting a signal indicative of the at least one detected angle, and a digital controller is provided which has an interface operable to receive the signal.
摘要:
A microcomputer performs a total of 100 sampling actions during a 1 sec sampling period for obtaining a plurality of battery voltage data V. In each sampling period, a minimum value .upsilon.min and a maximum value .upsilon.max are stored in a RAM 53. A peak value VMAX, used for detecting a peak battery voltage in the charging operation, is renewed by a largest data among the sampled minimum values .upsilon.min. A differenc .DELTA.V between the peak value VMAX and the maximum value .upsilon.max is calculated the end of each sampling period. And, when the calculated difference .DELTA.V exceeds a predetermined value, a judgement is made that the battery is fully charged.
摘要翻译:在1秒采样周期内,微计算机执行100次采样动作,以获得多个电池电压数据V.在每个采样周期中,最小值upminon和最大值up max max被存储在RAM 53中。峰值 用于检测充电操作中的峰值电池电压的值VMAX由采样的最小值upminon中的最大数据更新。 在每个采样周期结束时计算峰值VMAX和最大值upsilon max之间的不同DELTA V。 并且,当计算出的差值DELTA V超过预定值时,判断电池是充满电的。
摘要:
A miter saw for displaying angle of a cutter blade cutting the workpiece. The miter saw has a base mounting a workpiece thereon, a movable member movably supported to the base, and a cutting unit connected to the movable member for supporting the cutter blade. A positioning portion is associated with the movable member and provides a predetermined nominal position of the movable member with respect to the base. The predetermined nominal position includes a reference position and other positions labeled angle. A detector detects the position of the movable member with respect to the base. A processor sets an angle between the reference position and the predetermined nominal position as a displayed moving amount when the movable member is positioned at the predetermined nominal position. Otherwise, the processor computes the moving amount based on the output signal from the detector.
摘要:
To provide inexpensive and economic battery chargers with excellent productivity, a control circuit board for the battery charger is produced so as to be usable in common for both the battery chargers with a cooling device and the battery chargers without a cooling device. In the control circuit board, a cooling device detection circuit is provided for detecting whether or not the cooling device is provided. An average charge current to be applied to a battery pack to be charged is controlled depending on whether or not the cooling device is provided. The average charge current is further controlled depending on the type of the battery pack, i.e., whether it is of a small rated capacity or of a large rated capacity, and on a rate of change in battery temperature at the time of start of charging.