| 摘要 |
PURPOSE:To ensure the steady oscillation of an extremely low frequency by adding the 2-step charging circuit and the switching element to the Schmidt trigger circuit. CONSTITUTION:The charging circuit consisting of resistance 25 and 35 plus capacitor 26 and 36 is added to Schmidt trigger circuit 18 along with switch element transistor TR31. With closure of switch 33, TR31 conducts. As a result, the potential of circuit 18 lowers at point (a) with point (b) set at a low level and transistor 28 cuts off, and then the oscillation stops. When switch 33 is opened, TR31 is cut off since point (b) features a low level, and capacitor 26 and 36 are charged via resistance 25 plus 25 and 35 respectively to raise the potential of point (a). As a result, point (b) features a high level to make TR31 conduct with the potential lowered at point (a), and point (b) features a low level. These actions are repeated to continue the oscillation. Thus, a low-frequency oscillator circuit can be obtained with excellent temperature characteristics. |
