| 摘要 |
An airless spray gun includes a pump piston and a drive arrangement formed of a coil and a swinging armature for connection to an alternating current network. A suppression circuit is provided for periodically suppressing an arbitrarily selectable whole number of successive half-waves of the alternating current. A plurality of phase control circuits corresponding in number to the number of suppression stages is also provided, each of the phase control circuits effecting a phase-angle of fixed size and being permanently connected to one of the suppression stages to supply a phase-delayed signal of selected frequency to the drive arrangement. |
