Ref. : 2V/471A Half-Wave Mercury- Vapour Rectifier Code: 872A (CV1449) This rectifier is equivalent to the U.S.A. 872/872A and F353A< types. CATHODE Oxide-coated filament, shielded Filament voltage 5 Vv Nominal current 7.25 A Minimum cathode heating time 1 min MECHANICAL DATA Maximum overall! length 216 mm Maximum bulb diameter 62 mm Base Large 4-pin bayonet Socket 4009C or 4039A Net weight 225 g Mounting position Unrestricted< MAXIMUM RATINGS Maximum peak inverse voltage 10 kV Maximum peak anode current 5 A Maximum average anode current 1.25 A Maximum volt drop 14 Vv Condensed mercury temperature range with forced ventilation 15 to 70 c The above ratings apply to operation with a choke-input filter and a supply frequency of 50 c/s. May 1958 2V/471A1 1958 Standard Telephones and Cables LimitedRef. : 2V/471A Half-Wave Mercury- Vapour Rectifier Code: 872A (CV1449) CATHODE HEATING TIME Ambient Temperature 10 to 20C =| 20C and above Minimum pre-heating period 2 minutes 1 minute MAXIMUM PEAK INVERSE VOLTAGE RATINGS AND CONDENSED MERCURY TEMPERATURE Natural Ventilation 15 to 50C 15 to 45C Forced Ventilation 15 to 70C 15 to 60C Peak inverse Voltage Up to 5kV to 10 kV After shipment or transit the valve must be pre-heated for not less than 30 minutes before any anode voltage is applied, so that the mercury may be distributed correctly. The temperature limits given under Natural Ventilation are only valid for unrestricted natural ventilation. Forced air cooling is recommended and is required for operation up to the limit of condensed mercury temperature. Before putting a valve of this type into service it is recommended that reference be made to the General Information Section K in the introduction to this handbook. May 1958 2V/471A2Ref. : 2V/471A Half-Wave Mercury- Vapour Rectifier Code: 872A (CV1449) TYPICAL OPERATING CONDITIONS Maximum | Maximum | Maximum A.C. D.C. D.C. Circuit No. of Input Output Output valves | Voltage | Voltage | Current (Ve.m.s.) (Y) (A) Single Phase Full-Wave 2 3535 3200 2.5 Circuit No. 1 Single Phase Full-Wave Bridge 4 7070 6400 2.5 Circuit No, 2 Three Phase Half-Wave 3 4080 4780 3.75 Circuit No. 3 Three Phase Double Y Parallel 6 4080 4780 75 Circuit No. 4 Three Phase Full-Wave 6 4080 9570 3.75 Circuit No. 5 The above tables suitable circuits for this rectifier, and shows their safe maximum input and output conditions. The values are based on sine wave input and the use of a suitable choke input filter. This rectifier being directly heated, it is recommended that the output circuit be taken from the mid-point of the filament supply transformer secondary winding. For details of the circuits referred to see sheet K8 in the intro- duction to this handbook. May 1958 2V/471A3Ref. : 2V/471A Half-Wave Mercury- Vapour Rectifier Code: 872A (CV1449) TOP CAP CT.3. BASING 1 NO CONNEXION 2 FILAMENT 3 NO CONNEXION A 4 FILAMENT TC ANODE / =f ____. LARGE 4 PIN BAYONET. UU Dim: [ MILLIMETRES INCHES A [215-9 MAX: bls MAX: B 61-9 MAX: | 2 26 MAX: NOTE-BASIC FIGURES ARE INCHES May 1958 2V/471A4