I like the circuit. The meter will need to be either analog or battery operated. The impedance of the meter at the desired amperage setting will need to be less than about 500 Ohms. I imagine that this is not a problem for a digital meter. It might be a problem for an analog mili ammeter. The cheap analog meters that would work do not specify their impedance.
Ken Harstine
413-250-8298
Ken Harstine