AUTOMATIC POWER SUPPLY ON/OFF CIRCUIT OF BIOCHEMICAL AUTOMATIC ANALYZER

摘要

PURPOSE:To obtain high reliability by turning a power supply switch OFF only when both of the AND signal of the contact signal of a time switch and the OFF signal from a CPU and the automatic OFF signal '1' level signal from the CPU are active. CONSTITUTION:A time switch 210 always receiving the supply of power from an AC power supply 100 outputs an ON signal 211 to a power supply ON/OFF drive means 230 when set automatic power supply ON time arrives and outputs an OFF signal 212 to a power supply OFF control means 220 when OFF time arrives. The drive means 230 receives the power supply ON input signal 11 and turns a power supply switch 300 ON and turns the switch 300 OFF on the basis of the OFF input signal 221 from the control means 220. The power supply OFF control means 200 receives the AND signal of the OFF signal 212 from the time switch 210 and the power supply OFF signal 501 from a CPU 500 and sends the OFF signal 221 to the drive means 230 only when both signals become an OFF state. By this method, even when there is erroneous operation in one of both signals, the erroneous cutting of the power supply is not generated and high reliability can be obtained.