Classification- Dome-type bulb of glass, a white ceramic base with four-prong bayonet golden pins, oxide coated filamentary, mesh plate twin diode.

Application -It is designed to supply direct current up to 200 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 and 2.274B_A_+_01_en274B +

Nominal operating conditions and parameters

Filament voltage* ………………………………………………………… 5.0V

Nominal filament current ………………………………………………… 4A

Choke-Input filter

RiM-S Alternating voltage prelate ………………………………………… 550V

Tolal rectified current ……………………………………………………… 140mA

Condenser-Input Filter

RiM-S Alternating voltage prelate ………………………………………… 450V

Tolal rectified current ……………………………………………………… 120mA *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 3. Direct-voltage output characteristics are given in Figures 4 and 5. The characteristics of Figure 4 are for a choke-input filter such as is shown in circuit A and those of Figure 6 are for a condenser-input filter such as is shown in circuit B. 274B_A_+_02_en

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 ………………………………………… 250 mA

2 Max. R-M-S Alternating Voltage per plate ………………………… 660V

2 Max. Total Rectified Current ………………………………………… 200mA

Condenser-input Filter:

1 Max.R-M-S Alternating Voltage per plate ………………………… 450V

1 Max. Total Rectified Current ………………………………………… 200mA *4uF.Maximum filter input capacitance