| 摘要 |
PURPOSE:To use a normal operational amplifier which can be inexpensively and easily obtained by supplying a voltage of its measuring range by a voltage dividing resistor to the amplifier, and grounding the connecting point of the resistor in which its voltage is measured so that a high voltage is not applied to the amplifier. CONSTITUTION:Series resistors made of first, second, third and fourth resistors (Rm1, Rm2, Rm3, Rm4), (Rs1, Rs2, Rs3, Rs4), (Re1, Re2, Re3, Re4) are respectively connected between the electrodes of a main power source Em, a simmer power source Es to be supplied to a laser discharge tube V and the discharge tube V. The connecting points of the second and third resistors are grounded, and their divided voltages are respectively measured by operational amplifiers Am1, As1 and Ae1 to detect voltages between the electrodes of the sources Em, Es and the tube V. Thus, since the connecting points of the second and third resistors are grounded, normal amplifiers can be used, and special amplifiers as prior art are not necessary. |
