A permanent-magnet device for enabling a more uniform division of the scale of alternating-current indicating instruments to be readily obtained

The paper describes a method of employing the repulsion between like poles of permanent magnets to give the whole or the greater part of the controlling torque for an alternatingcurrent indicating instrument. The application of the device to electrostatic voltmeters in particular is discussed and the results of some tests on an experimental instrument are given. It is demonstrated that an approximately uniformly-divided scale is readily obtained without recourse to any special design of the operating mechanism.