As shown in Figure 12, adding a second resistor, RB, to the circuit of Figure 9 and connecting the trigger he threshold input causes the timer to self-trigger and run as a multivibrator.

• 象图12所表示的，给图9的电路增加第二个电阻RB，使其连接触发器，用阀值引起定时器自触发，使其象一个多频震荡器一样。