A voltage regulator having insert slots adopted for used on extension lines to stabilize electric current comprises a body which has an upper shell and a lower shell. Intervening separators are provided between positive and negative electrode plates arranged alternately in parallel to long lateral walls of the cell case. Subsequently, a circuit substrate used for the nonreciprocal circuit element can be smaller than conventional circuit substrates, and the assembly of the nonreciprocal circuit element is excellent. A reset input is received to remove the alert for a predetermined period of time.