| Software Support > Automated Projects |
| Getting ready to start rotating monitor setup |
| << < (2/2) |
| DaOld Man:
I have toyed with the idea of using a current sense circuit to detect when the motor "dead ends" against the mechanical stops, but havent created any real time circuits, although I dont think it would be too difficult. My proposed circuit monitors a voltage drop across a low ohm resistor in series with the motor. If voltage across the resistor jumps up to a selectable level, the circuit outputs a signal that motor has reached its destination. (The motor stalls, shooting current up, voltage across resistor jumps up too. E=I*R) There are some problems with this though. The first I can think of is that it's not healthy for the motor to come to a dead head stop, it can generate heat in the motor and stress the windings. Also coming to a physical stop every time can put stress on the bearings of the motor and your rig. Not to mention the stress of the increased current on the drive and the wiring. Im also interested in how the controller senses that the motor has reached its destination. Epetti, can you elaborate on it? |
| epetti:
I hadn't gone into a deep dive of how it would work. Reading through it again, I may have misinterpreted how DNADan's was working. I got the impression that the control for detecting a stop was built into the controller that he ordered from polulu. Reading through the info on the controller, though, it looks like just the wiring and controls for the limit switches are directly built into the controller, but you would still need limit switches. Having said that, there are plenty of examples of safety mechanisms on existing commercial devices that stop and reverse when they detect impediment. Seems like a solvable problem. Just haven't put any thought into it. |
| DaOld Man:
Bump. Any progress? |
| epetti:
Sorry I never looped back with this thread. Finished the cabinet about four months ago. Project thread is here: http://forum.arcadecontrols.com/index.php?topic=131671 That thread includes links to the other posts I used as inspiration for the rotating part. Never ended up doing an automated stopping mechanism. Just has two micro switches at 90 degrees that signal the motor to stop when they're hit. Works great. |
| Navigation |
| Message Index |
| Previous page |