| 摘要 |
PURPOSE:To obtain an apparatus capable of self-protection against abnormal voltage by keeping a circuit containing a liquid level detection electrode electrically connecting to an oscillation circuit and a switching circuit, employing two current transformers. CONSTITUTION:The output of an oscillation circuit 5 is connected to the primary winding 6a of a first current transformer 6 while the secondary winding 6b thereof 6, a pair of liquid level detection electrodes 12a and 12b through the primary winding 8a of a second current transformer 8 and distributing wires 14a and 14b. The secondary winding 8b of the second current transformer 8 is connected to a switching circuit 9 comprising resistors 9a and 9b, a transistor 9c, a capacitor 9d and a relay 9e and the output of a power supply circuit 4 comprising a transformer 4a, a diode 4b and a smoothing copacitor 4c is connected to the switching circuit 9 and the oscillation circuit 5. |
