Bravia
At present I am working on a Motorised Wheelchair Base unit using the original Motors,these are pretty powerful and can inflict a lot of damage if great care is not taken. Using my EZ-B to control its movement ,although it operates quit well, but for example if I loose connection for any reason the Robot can now be a monster out of control. To provide a safety feature to remove power from the motors one could use a micro switch on front & rear and once it meets an object it will stop. Good idea ,small problem it may be travelling at speed and you could sustain a serious injury if you happen to be that object.
My solution under construction at present, is use a Car Parking Radar which is stand alone and is not dependent on Ez-b or pc connection . To put it simply if an object is say within 10 ins of Robot ,power is cut off to motors. Then it can be reset through EZ-B if necessary
Did a test on switching off current on wheelchair controller only 1.3ma So Now I can loop a number of relays to shut down the motors in an emergency. big plus not switching high current also these relays have opto couplers for isolation
:P
I agree with the idea and love the setup. I didn't go that deep for my bot. I just used to cheap big red E-stop button on it.. But that only works when some one is there. But this was my first scratch build so it wasn't running on its own. The one I am starting on now with some of the parts of the old one will move later so I am going to add your ideas into (if you don't mind, thanks)..
you are more than welcome to use also once I have circuit complete I will upload a schematic Pat
Pat That would be great. Thank you for the hard work.
Thanks for the compliments on my robot. Have you got any pictures of your robot yet? I would enjoy seeing it. That is interesting about the charging circuit for your wheelchair. My wheelchair has an onboard charger. I will have to look into that. It may have a similar setup. I wouldn't want to be pulling the power pack on a regular basis, but I do want to have a last resort method to stop him if he gets any crazy ideas. (Anyone who saw the first episode of "Lost in Space" will understand). Incidentally, I got the same relays for mine, except the "16" size. I haven't done anything with them yet. Be aware that when you power up the board they all flip. The controller de-energizes each relay on command. This isn't a huge issue. Because they are SPDT; you can wire them to either side, but they do draw power when they are in the "rest" position. You also have to plan around it for startup and shut down. Dave Shulpius bought some and pointed this out to me.