Electromagnetic Field (EMF) Sensor Using Three Transistors Demonstration

This is a demo of the electromagnetic field sensor using three transistors. The base of the second and third transistor are directly coupled to the emitter of the previous transistor. The EM field is detected by the indication of the LED connected to the third transistor. The base of the first transistor is connected to a sensing tip made of a metal strip or enameled wire. When the sensing tip is brought near an electromagnetic field, near electric cables or lines, (never touch it) the LED indicates showing the field.

[@rycka88]

Sir

[@tnamen1307]

Sir can you please help me...
Please kindly help me with wiring diagram.
I need a diagram of ne555 which will monitor 2 different voltages, and gives output signal 1 when the present reading voltage is between the 2 monitored voltages. For example, if one voltage is fixed at 13V and another voltage at 15V, but the present reading voltage is 14.5. So, it's between 13 and 15, hence, it will constantly output a signal 1.
But if the present reading voltage is below 13V OR above 15V, then the IC will not output anything. Please help me with the diagram 🙏🙏🙏

[@cipher-1]

You must do a "windows comparator" i think so many in internet