H03G3/00—Gain control in amplifiers or frequency changers
H03G3/20—Automatic control
H03G3/22—Automatic control in amplifiers having discharge tubes
B—PERFORMING OPERATIONS; TRANSPORTING
B60—VEHICLES IN GENERAL
B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
B60T15/00—Construction arrangement, or operation of valves incorporated in power brake systems and not covered by groups B60T11/00 or B60T13/00
B60T15/02—Application and release valves
B60T15/36—Other control devices or valves characterised by definite functions
B60T15/46—Other control devices or valves characterised by definite functions for retarding braking action to prevent rear vehicles of a vehicle train overtaking the forward ones
Bias voltage control circuitry for avalanche photodiode taking account of temperature slope of breakdown voltage of the diode, and method of adjusting the same