What kind of waves are these?
simulate this circuit &ndash; Schematic created using CircuitLab

This is the basic schematic of a solenoid pump except it has very little mass and produces a triangle wave.  Somehow...gating off the recoil and back EMF you can get a quasi ramp wave with dead band.

The H sweep on a scope is somewhat similar except the retrace is much smaller and symmetrical with a linear bipolar ramp from the flyback transformer.

Here is how I synthesized your waveform.