摘要 |
A set of electronic frames capable of detecting an external device includes a main frame and an external frame. The main frame includes an R-C circuit with a detecting pin, a resistor coupled to the detecting pin, and a voltage comparator for comparing the potential at the detecting pin and a reference potential. The external frame includes a connecting port coupled to the R-C circuit of the main frame. The connecting port includes an identifying pin coupled to the detecting pin, and an R-C circuit coupled to the identifying pin. The voltage comparator is utilized for comparing the potential of the first end of the resistor of the main frame and the reference potential after each predetermined time gap
|