Lord. W. Harold

Systems and ballast apparatus for operating fluorescent lamps at preselected levels of illumination

Test transformer for ring-type magnetic cores

Nonlinear resonant electrical circuit

Gaseous electric discharge apparatus

Light responsive circuit controller

Self-pulsing oscillator

Apparatus for starting and controlling discharge devices

Excitation circuit for flectric valve apparatus

Three-phase saturable reactor type ballast

Apparatus for magnetic core testing