PROTECTION SYSTEM FOR BATTERY AT BUS TERMINAL

摘要

PURPOSE:To protect the memory contents by outputting an alarm signal to a CPU when the push of a release button is detected then outputting a signal to a memory buffer to inhibit the R/W operations of a memory when detection of the exclusion of a battery. CONSTITUTION:A release button switch 1 is used for taking out a battery, and a sensor 2 detects the come-off of the battery. These switch 1 and sensor 2 are connected to a control circuit 3 which is connected to a CPU 4 and a memory buffer 5. The power is always supplied to the circuit 3 and the buffer 5 from a secondary battery 6. Then the circuit 3 outputs an alarm signal to the CPU 4 with detection of the push of the button 2 and then outputs a signal to the buffer 5 to inhibit the R/W operations of a memory with detection of the take-out of the battery. Thus it is possible to prevent the destruction of the memory contents when a working battery is inadvertently excluded due to an operating mistake.