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Calculations for the rise of current in the primary circuit of a standard tall coil for battery ignition.


Identifier  ExFiles\Box 69\1\  scan0006
Date  30th April 1924
  
X8710

30.4.24.

R.R. BATTERY IGNITION.
STANDARD TALL COIL FIGURES.

A. {Mr Adams} RISE OF CURRENT IN PRIMARY CIRCUIT.

E = 8.00 volts

R = 2.53 ohms.

L = .0096 henry.

Then final current Co = E {Mr Elliott - Chief Engineer} /R = 3.16 amperes

and time constant t, = L/R = .003795 seconds

= time to rise to .632 x 3.16 = 1.99 amperes.

Initial rate of rise of current (di/dt)o

= E {Mr Elliott - Chief Engineer} /L = 833 amperes per second

i = 3.16 (1 - e^-263.5 t)

Contd.
  
  
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).


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