好学医电在线

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<section><section powered-by="gulangu"><section><section powered-by="gulangu"><section><section><svg viewbox="0 0 1 1"></svg></section></section><section><section powered-by="gulangu"><p><strong>明日复明日，明日何其多。</strong></p></section><section powered-by="gulangu"><p>○</p></section><section powered-by="gulangu"><p><strong>无畏的太阳</strong></p></section><section powered-by="gulangu"><p>○</p></section><section powered-by="gulangu"><p><span>医疗|学习|钻研|电子电路|原理</span><br  /></p></section></section><section><section><svg viewbox="0 0 1 1"></svg></section></section></section><section powered-by="gulangu"><section><section powered-by="gulangu"><section><p><img src="image/20201019/90f585df297737edcfe663f87f010e4a_1.jpg" /></p></section></section><section powered-by="gulangu"><p><strong>欢迎关注</strong></p></section></section><section><section powered-by="gulangu"><section><p><img src="image/20201019/44956930c94b62aac85a8621e76f5dba_2.png" /></p></section></section><section powered-by="gulangu"><p><strong>好学医电在线</strong></p></section></section></section><section powered-by="gulangu"><p><strong>请留下你指尖的温度</strong></p><p><strong>让太阳拥抱你</strong></p><p><strong>记得这是一个有温度的公众号</strong></p></section></section></section><section powered-by="gulangu"><section><section><section powered-by="gulangu"><section><section><section powered-by="gulangu"><section><br  /></section></section></section><section><section powered-by="gulangu"><section><section><br  /></section></section></section></section><section><section powered-by="gulangu"><p>超声多普勒胎心监测仪（TX200la）</p><p><br  /></p></section></section></section></section><section powered-by="gulangu"><section><section><section powered-by="gulangu"><section><br  /></section></section></section></section></section></section><section><section powered-by="gulangu"><section><br  /></section></section></section></section></section><section powered-by="gulangu"><p><br  /></p></section><section powered-by="gulangu"><section><section powered-by="gulangu"><section><br  /></section></section></section><section><section powered-by="gulangu"><section><p><strong>故障现象</strong></p></section></section></section></section><section powered-by="gulangu"><p><strong>①接通外电源，按开机键没反应，屏幕没有任何显示，模拟测胎心没有任何声音，不接外电源用电池供电故障依旧。（无法开机）。</strong></p><p><strong>②可以开机，再次按开关键的时候无法关机，开机的时候，功能使用正常。（无法关机）</strong></p><p><strong>③开机状态下，测量胎心的时候，有声音，没有数值。</strong></p></section><section powered-by="gulangu"><section><section powered-by="gulangu"><section><br  /></section></section></section><section><section powered-by="gulangu"><section><p><span>分析过程</span><br  /></p></section></section></section></section><section powered-by="gulangu"><p><span><strong>一、原理</strong></span></p><p><span><strong><span>一、开机电路：由电池供电4.8V到电源管理分配芯片（C0=16Y）的输入端3脚。此时按下开关按键，给出开机信号到双D型触发器芯片（HEF4013B），芯片输出高电平（5V）到电源管理分配芯片（CO=16Y）的使能端4脚，此时电源管理芯片（CO=16Y）满足输入端5V和使能端5V的触发条件，从1脚输出5V电压到主板上各个电路中。</span></strong></span></p></section><section powered-by="gulangu"><section><p><img src="image/20201019/fb42978a1d59eeafd1061d02db3d640b_3.png" /></p></section></section><section powered-by="gulangu"><section><section><p><img src="image/20201019/d964260ba54b6f8516a288914c85eada_4.png" /></p></section></section></section><section powered-by="gulangu"><section><section><p><img src="image/20201019/5310c5cda8d0c936b0187e0f8bfd49d4_5.png" /></p></section></section></section><section powered-by="gulangu"><p><span><strong><span>二、数据传输电路：经探头过来的声音信号，由放大器放大运算后，经耦合电容输出到CPU上。</span></strong></span></p></section><section powered-by="gulangu"><section><p><img src="image/20201019/23c1e6383ddfb457a9ddf0b1eec778b6_6.png" /></p></section></section><section powered-by="gulangu"><p><br  /></p></section><section powered-by="gulangu"><p><strong>二、分析</strong></p></section><section powered-by="gulangu"><p><strong>①按故障现象描述可以判断主板没有得电。</strong></p><p><strong>②无法关机要么按键，要么开关机电路有问题，要么单片机程序有问题，但是设备功能使用正常，又可以开机，排除单片机，排除按键。</strong></p><p><strong>③没有数值，说明要么信号处理芯片或者外围电路有问题导致数据传输转换出现问题，要么信号根本没有产生，但是测量的时候有胎音说明信号是有的。</strong></p></section><section powered-by="gulangu"><p><br  /></p></section><section powered-by="gulangu"><section><section powered-by="gulangu"><section><br  /></section></section></section><section><section powered-by="gulangu"><section><p><strong>解决方法</strong></p></section></section></section></section><section powered-by="gulangu"><p><strong>①根据开机电路，可以将问题锁定在按键、电源管理芯片（C0=16Y）、双D型触发器芯（HEF4013B）上。万用表调至蜂鸣档检测按键正常，万用表调至直流电压档检测电源管理芯片1脚跟2脚电压0V输出，2脚跟3脚电压有5V输入，4脚跟2脚有5V电平。符合电源管理芯片（C0=16Y）工作条件但是没有输出，判定芯片坏，更换芯片已经修复。</strong></p></section><section powered-by="gulangu"><section><p><img src="image/20201019/1a9ab40280929396a3158f1dcc42ad29_7.png" /></p></section></section><section powered-by="gulangu"><section><p><img src="image/20201019/92f66e240c17ecf638af4033a05d5977_8.png" /></p></section></section><section powered-by="gulangu"><p><br  /></p></section><section powered-by="gulangu"><p><strong>②根据开机电路，检测开机信号途经的外围元器件正常，检测双D型触发器芯片（HEF4013B），没有5V高电平输出。具体波形需要示波器检测。更换芯片已经修复。</strong></p></section><section powered-by="gulangu"><section><p><img src="image/20201019/910f221cf11f6e6f51c62eae5addebd3_9.png" /></p></section></section><section powered-by="gulangu"><p><strong>③对数据传输电路研究还不是很深透，优先检测其外围电路，发现输出耦合电容破裂，更换后已经修复。</strong></p></section><section powered-by="gulangu"><section><section><p><img src="image/20201019/a17611e8ddd7e29b748162e540206be1_10.png" /></p></section></section></section><section powered-by="gulangu"><p><br  /></p></section><section powered-by="gulangu"><section><section powered-by="gulangu"><section><p>欢</p></section></section></section><section><section powered-by="gulangu"><section><p>迎</p></section></section></section><section><section powered-by="gulangu"><section><p>关</p></section></section></section><section><section powered-by="gulangu"><section><p>注</p></section></section></section></section><section powered-by="gulangu"><p><br  /></p></section><section powered-by="gulangu"><section><section powered-by="gulangu"><section><p><img src="image/20201019/90f585df297737edcfe663f87f010e4a_1.jpg" /></p></section></section></section><section><section powered-by="gulangu"><section><section><br  /></section></section></section></section><section><section powered-by="gulangu"><p>好学医电在线</p><p>和他的朋友们</p></section></section></section><section powered-by="gulangu"><section><section><svg viewbox="0 0 1 1"></svg></section></section><section><section><svg viewbox="0 0 1 1"></svg></section></section></section></section>