| 摘要 |
PURPOSE:To supply a DC voltage of the same as a supply voltage having correct polarity to a load even if connecting polarity of a DC power source is different. CONSTITUTION:The DC power supply circuit comprises a series circuit of a diode D1 and a relay RL1 so connected between a power source input terminal 11 and a power source input terminal 12 that energizing directions are reverse to one another, and a series circuit of a diode D2 and a relay RL2. When the diode D1 is energized, contact driving circuits RC1a and RC1b of the relay RL1 ON-connect contacts RS1a and RS1b of the relay RL1. When the diode D2 is energized, contact driving circuits RC2a and RC2b of the relay RL2 ON- connect contacts RS2a and RS2b of the relay RL2. As a result, even if connecting polarities to the terminals 11, 12 of the DC power supply 2 are different, a DC voltage of the same as the DC power supply voltage having correct polarity is supplied to a load 3 while protecting the load 3. |
