| Description | Date | Identifier | |
| Life cycle test comparing the performance of Dagenite and Exide batteries. | 21th Apr 1936 | Box 164 \ 4 img280 | |
| Graph showing the discharge curves for a Dagenite 6HZD13-5 battery at a 10-hour rate. | 21th Apr 1936 | Box 164 \ 4 img281 | |
| Letter to Peto & Radford regarding battery performance tests, lifecycle claims, and battery corrosion. | 10th Nov 1936 | Box 164 \ 4 img282 | |
| Graph showing discharge curves for an Exide 6 XCMR-13L battery. | 3rd Apr 1936 | Box 164 \ 4 img283 | |
| Graph showing the 10-hour rate discharge curves of 3-plate Phantom III batteries. | 3rd Apr 1936 | Box 164 \ 4 img284 | |
| Graph showing the high rate discharge curves for an Exide 6XCM R 13-IM battery. | 16th Mar 1936 | Box 164 \ 4 img285 | |
| High rate discharge curves for a Dagenite 6 HZO 11S battery. | 23th Apr 1936 | Box 164 \ 4 img286 | |
| Graph showing 10-hour rate discharge curves for an Exide 6XCMR 13-1ML battery. | 31th Mar 1936 | Box 164 \ 4 img287 | |
| Graph of discharge curves for a Dagenite 6-HZD 15-S battery at a steady 200 amp current. | 2nd Nov 1936 | Box 164 \ 4 img288 | |
| Experimental department report on comparative tests of Phantom III thin plate batteries. | 2nd Nov 1936 | Box 164 \ 4 img289 | |
| Internal memorandum regarding the examination and testing of new Marchal Type Lucas Headlights. | 3rd Nov 1936 | Box 164 \ 4 img290 | |
| Letter from The Chloride Electrical Storage Company regarding two suggested alternative devices for battery hold-downs in Bentley cars. | 3rd Nov 1936 | Box 164 \ 4 img291 | |
| Letter to The Chloride Electrical Storage Co. Ltd. to arrange a meeting in Derby to discuss test results. | 3rd Nov 1936 | Box 164 \ 4 img292 | |
| Letter from accumulator manufacturer Peto & Radford discussing battery life, plate thickness and testing comparisons. | 5th Nov 1936 | Box 164 \ 4 img293 | |
| Letter from Peto & Radford proposing the service testing of a 'sandwich' battery design. | 6th Nov 1936 | Box 164 \ 4 img294 | |
| Letter from Peto & Radford following up on a special battery with topping-up devices. | 6th Nov 1936 | Box 164 \ 4 img295 | |
| Letter from The D.P. Battery Company Ltd regarding particulars for Kathanode Corporation batteries. | 12th Nov 1936 | Box 164 \ 4 img296 | |
| Internal request to order two Exide batteries for experimental chassis 38-EX and 39-EX. | 13th Nov 1936 | Box 164 \ 4 img297 | |
| Request to order replacement Exide batteries due to faulty cells and cracked containers. | 13th Nov 1936 | Box 164 \ 4 img298 | |
| Letter from accumulator manufacturer Peto & Radford discussing the comparative performance and cycle life of their batteries versus Exide batteries. | 13th Nov 1936 | Box 164 \ 4 img299 | |
| Exide battery being sent to stores and returned to the makers for examination. | 16th Nov 1936 | Box 164 \ 4 img300 | |
| Changing the treatment of battery boxes from lead coating to anti-sulphuric paint. | 16th Nov 1936 | Box 164 \ 4 img301 | |
| Internal order for Exide batteries for the Electrical Experimental Department. | 1st Nov 1936 | Box 164 \ 4 img302 | |
| Letter to Chloride Electrical Storage Co. Ltd. requesting a missing enclosure from a previous correspondence. | 9th Dec 1936 | Box 164 \ 4 img303 | |
| Letter from accumulator manufacturers Peto & Radford arranging a meeting to discuss batteries. | 15th Dec 1936 | Box 164 \ 4 img304 | |
| Letter from the Experimental Department arranging a meeting with G.R.N. Minchin Esq. | 15th Dec 1936 | Box 164 \ 4 img305 | |
| Letter from an external supplier regarding life test results of an Exide battery. | 23th Dec 1936 | Box 164 \ 4 img307 | |
| Letter from The Chloride Electrical Storage Company detailing battery test results and analysis. | 23th Dec 1936 | Box 164 \ 4 img308 | |
| Coil failures in the USA and comparing service complaint procedures with the Cadillac Company. | 1st Jan 1931 | Box 164 \ 5 img001 | |
| Improvements in ignition coil design and experimental investigations into coils from other manufacturers. | 3rd Jan 1931 | Box 164 \ 5 img002 | |
| Containing remarks regarding the receipt status of Delco, De Jon, and Delco Remy coils. | 4th Jan 1931 | Box 164 \ 5 img003 | |
| Design and construction particulars for an experimental De Jon coil as fitted to Springfield Phantom I's. | 27th Jan 1931 | Box 164 \ 5 img004 | |
| Description of a bakelite moulding with a top tin flange for holding a coil in position. | 27th Jan 1931 | Box 164 \ 5 img005 | |
| Test report detailing electrical measurements for windings, including resistance, impedance, and heating tests. | 27th Jan 1931 | Box 164 \ 5 img006 | |
| Test results from intensive heating, preliminary breakdown, and primary current consumption tests on an electrical component. | 27th Jan 1931 | Box 164 \ 5 img007 | |
| Test procedure sheet for low voltage, secondary voltage, coil temperature, and endurance tests. | 27th Jan 1931 | Box 164 \ 5 img008 | |
| Page listing a final intensive breakdown test and the examination results of windings. | 6th Jan 1931 | Box 164 \ 5 img009 | |
| Letter from The M-L Magneto Synd. Ltd. regarding production tests of Ignition Coils. | 6th Jan 1931 | Box 164 \ 5 img010 | |
| Continuation sheet of a letter from M-L Magneto Synd. Ltd. regarding temperature testing conditions. | 6th Jan 1931 | Box 164 \ 5 img011 | |
| Graph showing the relation between sparking voltage and the diameter of the central electrode. | 12th Jun 1924 | Box 164 \ 5 img012 | |
| New ignition coil (No. L.I.12) with L.P.S. paper insulation for testing. | 8th Jan 1931 | Box 164 \ 5 img013 | |
| Test report on a standard ignition coil with its secondary insulated with L.P.S wax paper. | 9th Jan 1931 | Box 164 \ 5 img014 | |
| The continuation of a test on a coil, concluding it is an improvement over the standard. | 15th Jan 1931 | Box 164 \ 5 img015 | |
| Potential causes of battery ignition coil failures and design considerations. | 15th Jan 1931 | Box 164 \ 5 img016 | |
| Technical discussion on ignition coil design, spark plug gaps, and methods for improving insulation. | 15th Jan 1931 | Box 164 \ 5 img017 | |
| Methods for improving and testing coils, with reflections on past failures due to moisture absorption. | 5th Jan 1931 | Box 164 \ 5 img018 | |
| Extract from a monthly customer complaints report regarding ignition coils. | 16th Jan 1931 | Box 164 \ 5 img019 | |
| The results of tests conducted on two samples of enamelled secondary wire. | 17th Jan 1931 | Box 164 \ 5 img020 | |
| Comparing various types of enamelled wire. | 21th Jan 1931 | Box 164 \ 5 img021 | |
| Typed note discussing research on battery ignition coils by comparing them to X-ray coils. | 21th Jan 1931 | Box 164 \ 5 img022 | |
| Issues with magneto ignition, coil safety, and spark plug gaps on 25 HP and 45 HP cars. | 23th Jan 1931 | Box 164 \ 5 img023 | |
| Investigation into the cause of recent failures in battery ignition coils. | 28th Jan 1931 | Box 164 \ 5 img024 | |
| Technical discussion on the design and magnetic properties of ignition coils and their cores. | 28th Jan 1931 | Box 164 \ 5 img025 | |
| Ignition coil insulation materials, wire quality, and spark plug gap issues. | 28th Jan 1931 | Box 164 \ 5 img026 | |
| The experimental testing of ignition coils, discussing voltage measurements, failures, and testing methods. | 28th Jan 1931 | Box 164 \ 5 img027 | |
| Ignition coil development, discussing insulation, testing, and comparisons with American coils. | 28th Jan 1931 | Box 164 \ 5 img028 | |
| Table detailing the resistances and inductances of primary and secondary windings for various non-trembler ignition coils. | 24th Sep 1926 | Box 164 \ 5 img029 | |
| Forwarding a copy of a memo received from Brock regarding battery ignition coils. | 29th Jan 1931 | Box 164 \ 5 img030 | |
| Improvement, cost, and manufacture of coils in response to a memo from 'R'. | 21th Jan 1931 | Box 164 \ 5 img031 | |
| Battery ignition coils, specifically the expense of sectionalised windings and a request for manufacturer names. | 23th Jan 1931 | Box 164 \ 5 img032 | |
| Mr. Brock's remarks on battery ignition coils and the circulation of a related report. | 29th Jan 1931 | Box 164 \ 5 img033 | |
| Cover memo for an attached copy regarding battery ignition coils. | 29th Jan 1931 | Box 164 \ 5 img034 | |
| Particulars of construction for a standard ignition coil to D.72503. | 30th Jan 1931 | Box 164 \ 5 img035 | |
| Extract from a 10,000-mile report on chassis 18-GIV regarding the coil's performance. | 30th Jan 1931 | Box 164 \ 5 img036 | |
| Requesting road tests to measure the temperatures of ignition coils under running conditions. | 2nd Feb 1931 | Box 164 \ 5 img037 | |
| Test report on a Springfield De Jon ignition coil that failed during a standard heating test. | 2nd Feb 1931 | Box 164 \ 5 img038 | |
| Coil heat test failure, with a proposal to examine the failed coil and a request to test a replacement. | 9th Feb 1931 | Box 164 \ 5 img039 | |
| Examination report on a failed De Jon ignition coil. | 9th Feb 1931 | Box 164 \ 5 img040 | |
| The construction and specifications of a coil's primary winding. | 9th Feb 1931 | Box 164 \ 5 img041 | |
| Document with a sketch detailing the construction and insulation of primary and secondary windings on a core. | 9th Feb 1931 | Box 164 \ 5 img042 | |
| Page detailing the construction, materials, and weight of an electrical coil. | 7th Feb 1931 | Box 164 \ 5 img043 | |
| Request for an experimental test on an ignition coil using enamelled primary wire. | 7th Feb 1931 | Box 164 \ 5 img044 | |
| Instruction to amend a previous order and arrange for a standard ignition coil to be fitted to chassis 22-EX. | 7th Feb 1931 | Box 164 \ 5 img045 | |
| Laboratory tests comparing French and British sourced enamelled copper wire for ignition coils. | 1st Feb 1931 | Box 164 \ 5 img046 | |
| The bench testing of a Springfield De Jon ignition coil and its subsequent failure analysis. | 9th Feb 1931 | Box 164 \ 5 img047 | |
| Analysis of a coil's design, construction, materials, and primary winding specifications, including a cross-sectional sketch. | 9th Feb 1931 | Box 164 \ 5 img048 | |
| Specifications for the construction and insulation of a coil's secondary winding. | 9th Feb 1931 | Box 164 \ 5 img049 | |
| Cover letter for sending design details of Lucas, Delco Remy, and De Jon ignition coils. | 20th Feb 1931 | Box 164 \ 5 img050 | |
| The experimental testing of a coil with specific primary and secondary winding connections. | 3rd Mar 1931 | Box 164 \ 5 img051 | |
| Fault analysis of a D.72503 ignition coil returned for repair. | 3rd Mar 1931 | Box 164 \ 5 img052 | |
| Examination and test report on a Marelli distributor and contact breaker. | 1st Mar 1931 | Box 164 \ 5 img053 | |
| Test results of a unit, focusing on contact breaker noise and the condition of distributor points. | 3rd Mar 1931 | Box 164 \ 5 img054 | |
| Comparison test report between their own ignition coil and American-made De Jon and Marelli coils. | 17th Mar 1931 | Box 164 \ 5 img055 | |
| Specification for an insulation test of a moulded ignition coil case. | 17th Mar 1931 | Box 164 \ 5 img056 | |
| The comparative laboratory tests of Messrs. West's enamelled secondary wire. | 23th Mar 1931 | Box 164 \ 5 img057 | |
| Letter to Messrs. North & Sons, Ltd. concerning magneto primary windings and ignition coils. | 6th Mar 1931 | Box 164 \ 5 img058 | |
| Letter from North & Sons, Ltd. acknowledging correspondence and confirming an order of wire for magneto primary winding experiments. | 9th Mar 1931 | Box 164 \ 5 img059 | |
| Letter to Lucas Electrical Co. Ltd. inquiring about the origin of square or rectangular enamelled wire for ignition coils. | 16th Mar 1931 | Box 164 \ 5 img060 | |
| Record of the price paid for a Marelli coil and distributor. | 31th Mar 1931 | Box 164 \ 5 img061 | |
| Letter from M-L Magneto Synd. Ltd. concerning the source and availability of rectangular section enamelled wire. | 17th Mar 1931 | Box 164 \ 5 img062 | |
| Letter responding to an inquiry about square or rectangular section wire for experimental purposes. | 18th Mar 1931 | Box 164 \ 5 img063 | |
| Test report on a coil with an outside primary winding, detailing its failures and required modifications. | 4th Apr 1931 | Box 164 \ 5 img064 | |
| Design specification for an experimental coil, detailing the primary and secondary windings, iron circuit, and casing. | 4th Apr 1931 | Box 164 \ 5 img065 | |
| The bench testing of ignition coils with 44 S.W.G. finer gauge secondary winding, proposing further experimentation. | 5th Jun 1931 | Box 164 \ 5 img067 | |
| Request to produce two modified ignition coils with 20,000 turns for the 40-50 HP and 20 HP chassis. | 22th Jun 1931 | Box 164 \ 5 img068 | |
| Loan of a Lucas Ignition Distributor and Coil for testing. | 4th Aug 1931 | Box 164 \ 5 img069 | |
| Failure in standard ignition coils due to a short circuit and recommending reinforced insulation. | 3rd Aug 1931 | Box 164 \ 5 img070 | |
| Letter to Lucas Electrical Co. Ltd. regarding joint tests on ignition coils and the progress of a new windscreen wiper. | 14th Aug 1931 | Box 164 \ 5 img071 | |
| Test schedule and design particulars for a Lucas Type L experimental coil. | 17th Aug 1931 | Box 164 \ 5 img072 | |
| Test results for electrical windings, including continuity, quantities, and heating tests. | 17th Aug 1931 | Box 164 \ 5 img073 | |
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