The Pool and Brake Sensors

Looking back I can see I failed to mention how I integrated the Bafang motor with my bike brakes.  The bike has hydraulic operated brakes rather than cable, which means I can’t use the same type of cable sensor as the gear shift to detect brake applications.  To resolve this I purchased a pair of magnetic brake sensors.  You might ask “Why are brake sensors required?”  I want the motor to cut out when I apply the brakes.

I made a simple jig from scrap plywood to secure the motor and then connected it to the battery and display before turning on the power.

Hurrah, these is power to the display

Speed zero km/h.  Battery full.  Motor power set to the lowest at level 1.  Zero distance covered. 

I turned the brake lever to the vertical position and then used Araldite to secure five small neodymium magnets to the lever handle (A).  The sensor was then attached to the body of the brake (B)

           

A – Magnets

B – Brake sensor

C – Gap under sensor

As you can see in the above photo; I have a problem with the sensor.  It can’t sit flat with only three small points of contact.  I’m working on a solution.

However I have managed to correctly adjust the distance between the magnets and the sensor.  When I apply the brake by pulling the lever the distance between the magnets and the sensor increases.  The magnetic field connection is broken and the display records the application cutting power to the motor.

 

That’s how I did it.

Yesterday I was in the swimming pool.  But only because I had that job of filling the gap between the fibreglass top of the pool and the underside of the coping pavers.  Yes….. I waited for a hot day when the pool water was warm.

The gap was filled with expanding aerosol foam insulation.

I’m now waiting on another hot day (likely this afternoon) to get back in the pool and cut off the excess foam with a razor knife.

Meanwhile more work has been done on the pool water heating components.  The water heating panels have been inspected and I sealed all the cracks and gaps with adhesive.

The panels are large and heavy so I’ve put my field engineering training to use and designed a simple field machine using basic principles to get them onto the shed roof single handed. 

Using some of the surplus aluminium extrusion I made and fitted mounting brackets for the photovoltaic panel that will power the pump .

 

Those of you who live on boats know (or should know) that heat degrades panel output and an air gap under the panel is therefore useful.