75ZT Community

.............. another pose that would suit the 75............

http://www.youtube.com/watch?v=4h69qdt9YaQ

Touch sensitive door handles in chrome are quite tricky, most are painted plastic.

Interesting challenge though!

You could put a self adhesive copper strip along the back of the Rover 75 door handle. That works... as I found out when i was erm... experimenting recently

raistlin wrote:You could put a self adhesive copper strip along the back of the Rover 75 door handle. That works... as I found out when i was erm... experimenting recently

How are you sensing? resistance of the hand? That can be a problem when it rains, or is foggy, or anything else that makes the door handle wet.

Capacitive sensing is the way to go, but you still need a decent air gap to prevent water bridging the sensing elements.

Another alternative might be a beam break system, which isn't affected by damp on the surface, but does need to be kept clean to work. Quiescent current on these can be a bit of a problem, mind.

Touch sensitive opening would be a very nice addition, however without a handle, as shown in the demo vid, is really not an option, opening the door by grabbing the top or trailing edge completely defeats the subtlety of the modification. IMNSHO.
If the door were to open pneumatically, with the added possibility of stopping the door by hand as it opened to an appropriate point, I think that would be acceptable.

Change of resistance at the moment Duncan, although I have heard of developments in piezo technology which might be responsive to touch, ie. relatively low pressure

raistlin wrote:Change of resistance at the moment Duncan, although I have heard of developments in piezo technology which might be responsive to touch, ie. relatively low pressure

The piezo sensing idea is quite good though the quiescent is again quite high. They work by vibrating the sensor at ultrasonic frequency and sensing the resonance. When you touch them that shifts the resonance by damping (or at least damps it at the same frequency, not entirely sure) and the change is detected.

Edit:
http://machinedesign.com/article/new-to ... tacts-0908