| 摘要 |
PURPOSE:To decrease the number of component parts and to increase the reliability, by adding an off-delay timer to each changeover switch of an automatic-manual switching circuit of the computer of the like of a rocket engine combustion test device and thus securing the self-support of the on-off state via an auxiliary relay. CONSTITUTION:A chageover is carried out between the manual mode contact M and the automatic mode contact C by means of an automatic-manual changeover switch COS. When the manual operation contact PBM is first pushed, a relay X2 is energized with conduction of a circuit at the constant close contact X3b1. And a common relay X3 is energized by conduction of the circuits at normally opened contacts X2a1 and MXa2 plus a normally closed contact X1b1. Thus the self-support is ensured with conduction of a normally opened contact X3a3. Then relays X1 and X2 are not energized when the contact PBM is released, and the self-support is given to the relay X3. When the contact PBM is pushed again, the circuit at the contact X3a1 conducts with the self-support of the relay X3 to energize the relay X1. Then th relay X3 is not energized with an open of the contact X1b1. In such way, a chageover of modes is possible without any change of the on-off state. |
