FIELD: electrical engineering. SUBSTANCE: device has protective units, AND gate, indicating unit, first inverter, counter, and RESET button. In addition, it is provided with EXCLUSIVE OR gates unit, three EXCLUSIVE OR gates, sync pulse generator, three inverters, JK flip-flop, D flip-flop, twin register, decoder, as well as new connections. Each protective unit is connected, respectively, to second input of EXCLUSIVE OR gates unit whose outputs are connected to inputs of shift register. Output of shift register is connected to second input of first EXCLUSIVE OR gate whose output is connected to second input of AND gate and , through second inverter, to G input of decoder; sync pulse generator is connected through AND gate to second input of counter and, through third inverter, to C input of shift register. RESET button is connected to second input of second EXCLUSIVE OR gate and, through inverter, to R input of D flip-flop whose 
output is connected to first inputs of EXCLUSIVE OR gates unit and to input of first EXCLUSIVE OR gate. 
output of JK flip-flop is connected to last and first vacant bits of shift register. Carry output of counter is connected to first inputs of third and second EXCLUSIVE OR gates whose output is connected to C input of JK flip-flop, S input of D flip-flop, RE input of shift register, and, through fourth inverter, to R input of counter whose data outputs are connected through decoder to indicating unit. First bit of data inputs of counter is connected through third EXCLUSIVE OR gate to R input of D flip-flop whose output is connected to CE input of shift register. EFFECT: improved circuit arrangement of device. 3 dwg
