【单选题】
T68型镗床的进给电动机采用了___方法。
A. 频敏变阻器启动
B. 全压启动
C. Y一△启动
D. △一YY启动
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答案
B
解析
暂无解析
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【单选题】
T68型镗床的主轴电动机采用了___方法。
A. 频敏变阻器启动
B. Y一△启动
C. 全压启动
D. △-YY启动
【单选题】
T68型镗床的主轴电动机采用了___调速方法。
A. △-YY变极
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【单选题】
T68型镗床的主轴电动机采用了近似___的调速方式。
A. 恒转速
B. 通风机型
C. 恒转矩
D. 恒功率
【单选题】
T68型镗床的主轴电动机M1采用了___的停车方法。
A. 能耗制动
B. 反接制动
C. 电磁抱闸制动
D. 机械摩擦制动
【单选题】
T68型镗床的主电路、控制电路和照明电路由___实现短路保护。
A. 速度继电器
B. 中间继电器
C. 熔断器
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【单选题】
T68型镗床的主轴电动机由___实现过载保护。
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B. 过电流继电器
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D. 热继电器
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T68型管床主轴电动机的高速与低速之间的互锁保护由___实现。
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D. 热继电器常闭触点
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T68型镗床主轴电动机只能工作在低速挡,不能高速挡工作的原因是___。
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D. 熔断器故障
【单选题】
X62W型铣床电气线路的控制电路由控制变压器TC、熔断器FU2和FU3___、位置开关SQ1~SQ7、速度继电器KS、转换开关SA1~SA3、热继电器KH1~KH3等组成。
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T68型管床电气控制主电路由___、熔断器FU1和FU2、接触器KM1~KM7、热继电器KH、电动机Ml和M2等组成。
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D. 时间继电器KT
【单选题】
反相比例运放电路应加的反馈类型是___负反馈。
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三相可控整流触发电路调速时,要使三相锯齿波的波形高度一致,斜率相同,相位互差___。
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滞回比较器的比较电压是___。
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实用的调节器线路,一般应有抑制零漂、___、输入滤波、功率放大、比例系数可调、寄生振荡消除等附属电路。
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若使三极管具有电流放大能力,必须满足的外部条件是___。
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下列不属于常用输入单元电路的功能有___。
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下列不属于常用中间电子单元电路的功能有___。
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下列不属于集成运放电路线性应用的是___。
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集成运放电路非线性应用要求___。
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下列不属于集成运放电路非线性应用的是___。
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【单选题】
组合逻辑电路常用的分析方法有___。
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B. 真值表
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D. 以上都是
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组合逻辑电路的分析是___。
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过零比较器可将输入正弦波变换为___。
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组合逻辑电路的译码器功能有___。
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组合逻辑电路的编码器功能为___。
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下列不能用于构成组合逻辑电路的是___。
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集成与非门的多余引脚___时,与非门被封锁。
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B. 接高电平
C. 接低电平
D. 并接
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集成或非门的多余引脚___时,或非门被封锁。
A. 悬空
B. 接高电平
C. 接低电平
D. 并接
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集成与非门被封锁,应检查其多余引脚是否接了___。
A. 悬空
B. 高电平
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数码存储器的操作要分为___步进行。
A. 4
B. 3
C. 5
D. 6
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时序逻辑电路的分析方法有___。
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B. 列出驱动方程
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时序逻辑电路的驱动方程是___。
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时序逻辑电路的状态表是由___。
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下列不属于时序逻辑电路的计数器进制的为___。
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时序逻辑电路的计数器按与时钟脉冲关系可分为___。
A. 加法计数器
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时序逻辑电路的输出端取数如有问题会产生___。
A. 时钟脉冲混乱
B. 置数端无效
C. 清零端无效
D. 计数模错误
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时序逻辑电路的计数器直接取相应进制数经相应门电路送到___。
A. 异步清零端
B. 同步清零端
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