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ＨＡ８６８（ＩＶ）Ｐ话机改为双音频话机夏雄堂陈艾华本文将ＨＡ８６８（ＩＶ）Ｐ话机改制成双音频话机实际应用效果较好。被改制的这种话机是早期生产的脉冲式电话机，电路图见图１。它使用的脉冲拨号芯片是ＡＹ－９１５１Ｂ，９脚ＤＰ为脉冲发号输出端，１０脚ＭＳ为脉...
HA868 (IV) P phone to dual audio phone Xia Xiong Tang Chen Aihua This article will HA868 (IV) P phone into dual audio phone practical application is better. The phone was adapted for the early production of the pulse telephone, the circuit shown in Figure 1. It uses a pulse dialing chip is AY-9151B, 9 feet DP pulse output, 10 feet MS pulse ...