摘要 |
<p>A diaphragm pump wherein the diaphragm is deformable by the reciprocable armature of an electromagnet which is energizable at a selected frequency by a timer circuit and at random frequency by a pulse generator. The pulse generator is connectable with the electromagnet by a cable having separable male and female coupling elements which automatically deactivate the timer circuit when the male coupling element is inserted into the female coupling element. A selector switch is provided to deactivate the timer circuit independently of the coupling elements. A knob serves to adjust a potentiometer of the timer circuit simultaneously with closing of the selector switch so that the frequency at which the timer circuit can energize the electromagnet is reduced to a minimum value.</p> |