| 摘要 |
PURPOSE:To obtain a stable pulse signal by utilizing the difference between the ON time and the OFF time of a photocoupler so as to obtain a pulse signal in a pulse generating circuit generating a pulse at the phase inversion of two kinds of rectangular wave signals is opposite phase to each other. CONSTITUTION:A photocoupler 4a detects the level change in a power line U0 to generate a signal (c) and a photocoupler 4b detects the level change in a power line V0 to generate a signal (d). Since the leading time Tr is 2 micro sec and the trailing time is 45 micro sec approximately in figures (c, d), the period where both the signals are at '1' level exists for nearly 43 micro sec and a '0' level signal is sent from a NAND circuit 5 during this period as shown in figure (e). The signal is fed to a data transmitter 7 and used as a trigger signal. |
