Tower crane structure changing position limiter

The utility model relates to a tower crane structure shifting limiter, the structure of which is that the signal output port of an angle sensor is connected with an input port of an operational amplifier, which output is connected with the first input port of a singlechip through an A/D converter; a keyboard inputting circuit is connected with the second input port of the singlechip; the first output port of the singlechip is connected with the input port of a displaying driver and a LED displaying device; the second output port of the singlechip is connected with the input port of a clock circuit; the first output port and the first input port of the singlechip are connected with the input port and the output port of an alarming and controlling circuit respectively; the second output port and the second input port of the singlechip are connected with the input port and the output port of a data memory. The utility model has the advantages that the actual shifting value of the crane structure can be detected in real time and on line and be displayed directly; the actual measuring value is input for setting and adjusting on line; the utility model also has the advantages of easily setting and inquiring, being arranged in the cab due to small volume and easy assembling, broad application, applying on each crane which has requirements on structure shifting limitation.