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超声诊断仪用至一定年限,就会出现辉度显著下降的现象,即使把辉度调节旋扭至最大,也无法得到理想辉度的波形,以至不能进行诊断。在这种情况下,一般只能更换示波管。但更换示波管,有时往往受到没有备件或规格不一等客观条件的限制。能不能在不更换示波管的前提下,提高示波管的辉度使之满足使用要求呢?回答是肯定的。它的改装原理是:把扫描电路中受50赫交流电源同步的单稳振荡器,改装为频率为
Ultrasound diagnostic apparatus with a certain number of years, there will be a significant decline in the brightness of the phenomenon, even if the brightness adjustment knob to the maximum, can not get the ideal brightness of the waveform, and can not be diagnosed. In this case, the general can only replace the oscilloscope. However, the replacement of oscilloscopes is often limited by the lack of objective conditions such as lack of spare parts or different specifications. Can not be replaced without the premise of the CRT, CRT tube to improve the brightness to meet the requirements? The answer is yes. It’s modified principle is: the scanning circuit by 50 Hz AC power synchronization monostable oscillator, converted to a frequency of