Classification- Dome-type or Aubergine-type bulb of glass, a white ceramic base with four-prong bayonet golden pins, oxide coated filamentary, Solid plate or mesh plate twin diode. Application -It is designed to supply direct current up to 112 miliamperes from an alternating current soure. Dimensions -Dimensions, outline diagrams of the tube and bases, and the arrangement of electrode connections to the base terminals are shown in Figures 1, 2 and 3. 
Nominal operating conditions and parameters Filament voltage* ………………………………………………………… 5.0V Nominal filament current ………………………………………………… 2A Choke-Input filter RiM-S Alternating voltage prelate ………………………………………… 550V Tolal rectified current ……………………………………………………… 112mA Condenser-Input FilterRiM-S Alternating voltage prelate ………………………………………… 450V Tolal rectified current ……………………………………………………… 98mA *Alternating-current filament supply or Direct-current filament supply.Characteristics-Average characteristics The current-voltage characteristic of a single diode untie of the 274A /B tube is shown in Figure 4. Direct-voltage output characteristics are given in Figures 5 and 6. The characteristics of figure 5 are for a choke-input filter such as is shown in circuit A and those of Figure 7 are for a condenser-input filter such as is shown in circuit B.
Limiting Operation Conditions for Safe Nor simultaneous ratings Choke-input filter: 1 Max. R-M-S alternating Voltage per plate ………………………… 550 volts 1 Max Total Rectified Current ………………………………………… 140 mA 2 Max. R-M-S Alternating Voltage per plate ………………………… 660V 2 Max. Total Rectified Current ………………………………………… 120mA Condenser-input Filter: 1 Max.R-M-S Alternating Voltage per plate ………………………… 450V 1 Max. Total Rectified Current ………………………………………… 105mA *4uF.Maximum filter input capacitance
