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TCL HA868 Ⅲ电话机送话音量小的常见故障是:机内所用的送话器(MIC)性能变坏所致。送话器是一种声、电转换器件,常用为驻极体式,工作时应在其两端加上1.5～3V的直流电压。我们可用万用表的R×10Ω档测量它两端的正、反向电阻值,以判断其性能优劣。性能优良的送话器正向电阻应小于50Ω,反向电阻应大于2kΩ,如果测得的结果符合上述的数值,则表明其正常,便可继续检查如图1所示的送话器及相关元件的电路,若各元件均正常,但送话音量仍略嫌小,这时可适当微调一下VR201的阻值,使送话的音量满足要求即可。
TCL HA868 Ⅲ phone to send a small volume of voice is the common fault: the use of the microphone (MIC) performance deterioration. Microphone is a sound and electricity conversion devices, commonly used for the electret type, work should be added at both ends of its 1.5 ~ 3V DC voltage. We can use multimeter R × 10Ω file measuring both ends of the positive and negative resistance values to determine the performance of its pros and cons. The good performance of the microphone forward resistance should be less than 50Ω, the reverse resistance should be greater than 2kΩ, if the measured results meet the above values, it indicates that it is normal, you can continue to check the microphone shown in Figure 1 and related Components of the circuit, if the components are normal, but send the volume is still slightly small, then you can fine-tune the VR201’s resistance, so that the volume of the call can meet the requirements.