Bidet update

Our testing rig! Kevin’s mission this week was to get the touch sensor to trigger through the new seat (which activates the bidet). The bidet has to have a flow of water to turn on so we connected it to the shower.

New “normal” shape seat cut to fit neatly on top of Bidet seat.

The new seat was then drilled to fit a small stainless steel contact pin (a modified bolt) to activate the Bidet seat sensor when the seat is occupied.

[In theory, the bolt would be an extension of the human body and would work… then again perhaps not.]

Lots of different size, shape and materials were tested to try and get reliable activation of the capacitive sensor. The sensor either wouldn’t switch off, wouldn’t activate or worked for a while and then seemed to recalibrate and stop working. More testing needed with the unit properly earthed in case this is causing the voltages to float (not really expecting this to make any difference).

A little bit about capacitance. Capacitors store electrical energy – the human body has about 22 pico farads of capacitance. When your hand gets an electric shock from touching metal – that’s your body which has generated energy, stored it as capacitance and is now discharging it into another object. Ouch!! The energy will discharge if the object you touch is at a different voltage potential.

The bidet type sensors are devices that measure capacitance in the environment. Some types of these sensors establish a base line level – and when the level goes up (when the body touches it) this increase activates the switch. That’s how touch taps and other things work. Some of them even measure how long you touch the surface for and can tell a ‘grab’ from a ‘touch’.

It get’s even more technical according to what Kevin googled so we don’t really know the exact nature of the switching so watch this space…



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