Centrifugal Governing to 0.3 Per Cent.
Page 31
If you've noticed an error in this article please click here to report it so we can fix it.
PROMB'TED by the articles that have been by in this paper recently on the subject of governing by short-circuiting the h.t. ignition current, the Iso-Speedic Co., Ltd., Friar's Road, Coventry, has sent us a copy of its' publication dealing with the range of centrifugal governors bearing the same name as, the company and which it produces.
In doing so, it draws our attention to an undesirable feature of the electric device, namely, that the carburetter setting is.not varied. In the case of prolonged governing, our correspondent remarks, this practice is highly undesiiable a`nd gives rise to the need for another governor which controls the delivery of fuel to the engine.
The Iso-Speedie device is claimed to govern to within 0.3 per cent, of Onstunt speed; 5 per cent, is commonly regarded as a sufficient degree of accu racy, appears that hysteresis lag, due to internal friction, is almost entirely eliminated. Incorporated in this governor, and seemingly partly respoesible for its ern= ciency, is an hydraulic 'mechanism, operated by oil pressure, which modifies the relationship between the centri fugal weights and the throttle. In small petrol or oil engines the lubrication pressure system can be employed for this .purpose.
The governor is designed to be installed with the other engine auxiliaries, and it is conveniently compact, its dimensions being 51 ins. by 5f ins. by 74 ins. It weighs 181 lb. and is suitable for governed speeds from 700 r.p.m. to 3,500 r.p.m.