mc004
Newbie level 3
ht9200b
I design DTMF generator with HT9200B. But how can I interface the output of the HT9200 device to the telephone line? there is a schematic in HOLTEK web site.(**broken link removed** ) But there are 3 undefined transistor. What kind of transistors must be used in this circuits. thanks.
I design DTMF generator with HT9200B. But how can I interface the output of the HT9200 device to the telephone line? there is a schematic in HOLTEK web site.(**broken link removed** ) But there are 3 undefined transistor. What kind of transistors must be used in this circuits. thanks.