Whilst dismantling an old inkjet printer I discovered a
small pump that had been used to circulate ink to a local tank near
the printhead. I salvaged this pump and some of the fine bore tubing
in the hope that I could work out how to power the device from a
simple electronic circuit and battery.
My intention is to either use pushbuttons to deliver say 1
microlitre or 2 or 3... Or to dial up a dose on thumbwheel switches
such that a single button delivers a measured dose.
The printer was a "Brother type HJ-770" and the pump is a
diaphragm type operated by an armature that is in turn activated by a
coil that connects to the two tabs.
The picture is 2.77 x full size. I have no idea of the rated
voltage, but I will start my experiments at 5v and work up from there
using water as a test medium.
One thing confuses me at the moment and that is a lack of
obvious valves on either the inlet or outlet of the pump, nor can I
find any valves in any other parts of the original plumbing. The only
conclusion I have reached so far is that the inlet is radial to the
circular diaphragm chamber and the outlet is at a tangent to this
circular wall. Perhaps there is some subtle fluidic process that
causes one way flow.
Revised... 09 July 2001
Revised... 02 March 2002
