Voltage shunt regulator tube 150V
0C3 VR150 VT139 SG4S Va=150V 40mA
A WY-4P maintains a nearly constant output voltage of about 150 volts across itself over a specified current range. Before semiconductor Zener diodes and integrated regulators became common, these tubes were used to stabilise high-voltage DC supplies. 5mA min., 40mA max. 160V-185V starting Striking Voltage.