Electronic-relay answering circuit

It is an electronic -relay type answering circuit for five answering groups . This circuit has functions such as self-locking, sound and light display, and monitoring
time. The number of channels can be increased at will.
    In the figure, button SBe is a monitoring time button, controlled by the host. When this button is pressed, the audio circuit will sound, informing
"the time has come, stop answering the question"; the function of the button SB7 is that when the answer to the question is finished or the answer is stopped due to the time, the host presses
this button to restore the circuit .