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日本三荣公司生产的1E21型心电图机描记热笔损坏,由于是进口机,此零件不易买到,改用国产热笔代替,使用二年多效果良好。此机的热笔调温电路是一种带过流保护串联型电压调整电路,其电压调节范围5.2V～10.8V,流过标记笔和描记笔的最大总电流约0.98A(描笔的直流电阻约20Ω,标记笔约26Ω);当将调温电位器旋至最大时,过流保护管Q_(12)的基极电压达0.67V,Q_(12)进入导通状态,分流了Q_(11)的部分基极电流,使调整管的内阻增
Japan Sanei company produced 1E21 electrocardiograph hot pen damage, because it is imported machine, this part is not easy to buy, use instead of domestic hot pen instead, the use of more than two years of good results. This machine hot pen thermostat circuit is a series with overcurrent protection voltage regulation circuit, the voltage adjustment range of 5.2V ~ 10.8V, the maximum total current flowing through the marker pen and tracing pen is about 0.98A (pen brush DC resistance About 12Ω, marking pen about 26Ω). When the thermostatic potentiometer is rotated to the maximum, the base voltage of overcurrent protection tube Q_ (12) reaches 0.67V, Q_ (12) ) Part of the base current, so that the adjustment of the tube resistance increase