| 摘要 |
PURPOSE:To eliminate the need for a cooling fan by suppressing the generation of heat due to a current limiting resistance by obtaining a voltage to be applied to an input contact circuit from a commercial AC power source and by receiving a current to be supplied to the contact of the input contact circuit from another power source. CONSTITUTION:To diode-side anodes of photocouplers PC1, PC2-PCn, cathodes of diodes DC1, DC2-DCn are connected and to their anodes, resistances RB1, RB2-RBn are connected. For input connection resistances RA1-RAn, a commercial AC power voltage 100 or 200V is used. Further, a common step-down transformer TC is provided to input circuits at (n) points and its low-voltage side output EL is rectified and connected to the photocouplers PC1-PCn via the RB1- RBn in parallel to high-voltage circuits. Consequently, the power consumptions of the resistances RA1-RAn are reduced and the generation of heat is suppressed, eliminating the need for a cooling fan. |
