| 摘要 |
PURPOSE:To prevent a sudden change of an operation mode, by placing plural keys in order, and constituting so that the operation mode cannot be changed unless a key being in an adjacent relation is pushed. CONSTITUTION:When the electric power supply is put to work, a pulse whose potential becomes high termporarily is provided to control channels CH1, CH2, CH3 from a pulse generator IS. Therefore, outputs Q1, Q2, Q3 of flip-flop circuits F1, F2, F3 become ''H''. These outputs are current-added through resistance which have been preset by potentiometers VR1, VR2, VR3, and are fetched as cotrol outputs. In this case, light emission diodes D1, D2, D3 are lighted and display a control state. Subsequently, when touching an electrode b4, an input of a gate circuit G14 becomes ''H'', and an output Q4 becomes ''H''. Even in case of touching the electrode uncontinuously, however, a mode is not changed since one input of the gate circuit is ''L''. |
