电路元件BOM表 R1 100 Ohm 1/4W Resist R2 470 Ohm 1/4W Resistor R3 10k 1/4W Resistor R4 100K 1/4W Resistor R5 1K 1/4W Resistor C1 47uF Electrolyc Capacitor U1 78L05 Voltage Regulator U2 LM339 Op Amp L1 #47 Incandescent lamp with glass removed (See "Nos") D1 