Electronics - Height Recorder

This is to tell you about the height recorder I built in the second year. That would be September 2002.

Basically it had controlling electronics, a frame fixed to the wall for a slide, a stepper motor, a pulley mechanism that moves a Micro-switch with a over mounted on an Aluminum pipe... Aaargh!!!

Ill try to get pictures later. its dismantled somewhere in college waiting for me to find it and give it life again:)

basically the electronics consists of 3 sections:-

section 1:
Controller... produces a pulse train (oscillator hooked up around a Schmidt trigger NAND gate) and sends simultaneously to both the stepper driver and the counter. Direction is set/reset using limit switches mechanically placed on the slide and goes to an RS flip flop built around 2 more NOT gates...

section 2:
Stepper driver... simple enough... uses a decade counter to generate the pulse sequence and a DPDT relay to switch sequence for reversing direction.

section 3:
up/down counter... with built in display driver... must be set to proper height on each power on using a separate sync switch provided on the front panel... display is calibrated to work to a resolution of 1mm and is in centimeters


Scratch built as usual... designed as well... finally put some use to those silly MS flats they buy in the college and make us toil over in the first year:)
cut, welded, drilled holes and mounted on the wall.

To fashion pulleys u need a lathe.. that's just what I got to use. course NOW, with silly ISO related imposition its not allowed for a Electrical guy to use the stuff in the Machine Shop. damn mechanical freaks think they know squat about 'em:)

Crazy freakin' scheme to pull the cross bar from both sides using a SINGLE wheel... funniest was the way I had to get the rope from one side to go over the inner pulley on the OTHER side...

Cross Bar:
Alum pipe with grooves cut in the sides, a sheet for the switch to sit on, the contacts from a terminal block to extend the lever, a welding electrode as lever, twine at the other end to hold the lever at the BDC:)

If you're still in you're senses and want to know more... feel free to mail at mail@cselian.com