| 摘要 |
PURPOSE:To omit a semi-fixed resistor and also to simplify the control of an electronic circuit by connecting previously an element incorporating a connection line which can be fused with an external current to a control element and flowing said external current when necessary after detecting a prescribed drive state of the electronic circuit. CONSTITUTION:Resistors 11-14 are connected to a DC power supply in a circuit 2 at the preceding stage, and resistors 12 and 13 serve as control elements and have resistance value much less than other resistors 11 and 14. Connection lines 17 and 18 are previously connected in parallel to resistors 12 and 13. These lines 17 and 18 can be easily fused by a current. When an electronic circuit 10 is controlled, the circuit 10 is activated. Then a detection circuit 5 decides the active state of the circuit 10. When the normal working of the circuit 10 is decided, both lines 17 and 18 are kept as they are. While a current is supplied to the line 18 from a control circuit to fuse the line 18 if it is decided that the resistance value at the earth side should be increased than that at a point Q. |
