From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Inquiry to General Electric Co. for specific power rectifying valves for high voltage tests.
| Identifier | ExFiles\Box 41\2\ Scan028 | |
| Date | 15th October 1926 | |
| X3646. To Wd.{Mr Wood/Mr Whitehead} from EFC. EFC3/T15.10.26. Would you please write to The General Electric Co. to enquire for further particulars of any power rectifying valves which they produce. We have their 'Broadcasting Valve' Catalogue in which particulars of one power rectifying valve [handwritten: Type U3] are given on p.38. We require a valve specifically for the purpose of high voltage D.C. tests of insulation, and one which will be utilised with a 2,500 volts R.M.S. supply from a high tension transformer already in our possession. Type U3 valve as listed has an emission of 80 milliamperes and will withstand a back pressure of 3,000 volts. The filament voltage is 5.5. We require a valve with an emission which need not be greater than 25 milliamperes, but which will withstand a total maximum back pressure of 7,000 volts, this figure representing twice the peak value of a 2,500 R.M.S. volt supply. We would prefer the filament voltage to be 4.0, as we are desirous of running this valve off a 4-volt accumulator without the necessity of any controlling resistance. We should like information from them as to what type of holder would be necessary for the valve recommended. For your own information only, it is our intention to make up one or two rectifying units consisting each of one such valve, battery, condenser, terminals, etc., one of which such units may be passed over to the Production | ||