This circuit is a regulator circuit. 1N4001: maximum average forward current (A): 1, peak reverse voltage VRRM (V): 50, maximum cycle positive pressure drop VFM (V): 1.100, maximum non repetitive surge current IFSM (A): 30, maximum reverse current IR (mA): 0.010, package / temperature (c): DO41/-65~175.
9014 triode parameters: the maximum dissipative power of the collector PCM = 0.4W (Tamb=25 C), the maximum permissible current ICM=0.1A of the collector, the base electrode breakdown voltage BVCBO=50V, the Collector Emitter Breakdown Voltage BVCEO=45V, the emitter base breakdown voltage BVEBO=5V, the collector emitter saturation voltage drop VCE (SAT) =0.3V (IC=100mA; IB=5mA). The base emitter saturation pressure drop is VBE (SAT) =1V (IC=100mA; IB=5mA), the characteristic frequency is fT=150MHz, HFE:A=60~150; B=100~300; C=200~600; D=400~1000.The regulator circuit based on 1N4001 chip is as follows: