Don't like the adverts?  Click here to remove them

Oil Pressure sender



Both contacts move.
One contact (lets call it D) is on the diaphragm and the amount it moves is
proportional to pressure, more pressure greater movement.
The other contact (H) is on the bi- metallic strip with the heating coil.
This also moves.
I would say yes it can close less or more. As pressure increases, the
diaphragm deflects to a greater degree and contact(D) moves more and pushes
the opposite contact (H) back
When oil pressure is present, contact D moves to meet contact H. This
causes current to flow through the heating coil on bi metallic strip, so
moving contact (H).
Contact H moves away from contact D opening the gap. No current, no
heating, contact closes again.
At a different pressure, then the amount of deflection of the strip required
to break the contact is different. Deflection is proportional to heating
and therefore contact time.
Is it working like an RC time constant circuit. Instead of charge/discharge
cycle, we have heat/cool cycle of the bi metal strip????
Hello Neil,
Pulse rate determined by pressure? How is pressure translated into movement
closing the contacts? If the membrane causes the contacts to close under
pressure, it can't close it less or more. It's either ON or OFF.
OK, it's all too complicated for such a simple gizmo. When I have a moment
I'll hook up a scope to the sender and we'll get a better picture.


On 6/7/05, Neil Paisnel <[Email address removed]> wrote:
Aha! It has two contacts! Even more bl00dy complicated. I still need a
while to play with the scope.
Roman (London, UK)
'92 HDJ80