Подскажите, плиз:

В дизельном двигателе есть регулятор оборотов двигателя.

Исходник:

LEAD CIRCUIT & SOFT COUPLING Switch 1(C1) controls the “Lead Circuit”. The normal position is “ON.” Move the switch to the “OFF” position if there is fast instability in the system. Switch 2(C2) controls a circuit designed to eliminate fast erratic governor behavior, caused by very soft or worn couplings in the drive train between the engine and generator. The normal position is “OFF.” Move to the “ON” position if fast erratic engine behavior due to a soft coupling is experienced.

Вопрос: как перевести Lead Circuit? Ведущая цепь? Питающая цепь? Задающая цепь? Или что-то совсем другое?

Спасибо.