filament voltage การใช้

• Emission may usually be restored by raising filament voltage.
• Tube-based transmitters must have power applied in the proper sequence, with the filament voltage applied before the anode voltage, otherwise the tubes can be damaged.
• Early TRF sets had typically two or three tuning knobs and tube filament voltage-control rheostats, all of which had to be set correctly to receive a station.
• Upon energisation of the filament only with the rated filament voltage ( 1.5 V ), in a darkened room you can just see it glowing a dull red.
• Later ( late 1920s ) TRF sets had ganged tuning ( one knob was used to control all stage tuning capacitors simultaneously ), AC house current operation, and eliminated the filament voltage adjustments.
• The "'1st element "'is a number specifying filament voltage in volts ( rounded off to the nearest whole number ), or, for cathode-ray tubes, the screen diagonal or diameter in cm ( rounded-off to the nearest whole number ).
• The "'1st element "'( from left to right ) is ( for receiving tubes ) a number specifying filament voltage in volts ( rounded to the nearest whole number ), or ( for cathode-ray tubes ) the screen diagonal or diameter in centimeters ( rounded to the nearest whole number ).
• The term comes from the days of valve ( tube ) radios when it was common practice to use a dry battery for the plate ( anode ) voltage and a rechargeable lead / acid " wet " battery for the filament voltage . ( The filaments in vacuum tubes consumed much more current than the anodes, and so the " A " battery would drain much more rapidly than the " B " battery; therefore, using a rechargeable " A " battery in this role reduced the need for battery replacement.