One of the load limiter circuits using transistors

One of the load limiter circuits using transistors     is shown in Figure 18-5. It can control 1~10A load as needed. Adjust the potentiometer RP to change the action setting value. When the set value is exceeded, the load circuit will be cut off and a power-off alarm will sound. The delayed power restoration time is determined by Rz and C3 . If the load still exceeds the set value, the power will be automatically cut off and the above process will be repeated.     The current transformer TA can be made by using an old transformer or a manganese-zinc magnetic coil, with 2 turns on the primary side and about 600 turns on the secondary side.