Drawer Slider Robo Foucault Tester
The robotic Foucault Tester was the brain child of James Learch. For information about his Robo go here.
I have a loooong way to go with this page as well as better documenting the circuit and stand.
The new stepper circuit (middle) with a stepper motor (bottom) and a PIC circuit (top) issuing commands to test the stepper circuit. After talking with James Lerch about his circuit he realized that the clamping diodes were not needed with the IRF540s, which have them built-in. A signal 12v, 1A power supply feeds the circuit and a 7805 is used to supply the 5v that is needed for the 74HCT541. The 74HCT541 (in the socket) is intended to be a sacrificial part in case 12v is fed back to the PC - it blows instead of your parallel port.
If you're not into stepper circuits this one is easy. There are eight wires from the parallel port going into it and eight control wires going out to the stepper motor (four for each stepper plus Power). When the PC sends a 5v signal over one of the control wires (ON) the controller board allows 12v to flow on the matching wire to the stepper. The board is really a fast, digital ON/OFF switch that has eight switches.
Above is the first level of the platform that controls distance to the mirror.
Next, is the second level that controls cutting the knife edge in and out (side to side).
Finally, the final level holds the camera, knife, alignment laser and LED. All controls were placed to match the Lab's Robo. The first level uses a 1/4" x 20 tpi rod and the second level uses a 1/4" x 28 tpi rod, again, matching the Lab's Robo. The overall size id bigger than what is at the lab. Partially because the drawer sliders are bigger and partially because I'm using a old, huge full-size VHS camera that has been in my closet for years.
Here's the to-do list: