Re: tool changer logic- mathematical challenge

OK I was right, although I don't like the description of it being a
C, that is what confused me in the first place. Surely a disk with
a segment cut out makes things easier to understand.

Anyway here is an idea:

You have a pulse to index the toolchange, this feeds into a binary
counter chip. ie. pulses in and binary out, you need three bits:

ABC
000 Tool position 1
001 Tool position 2
010 etc
011
100
101
110
111

(actually these bits could come straight from the PC??)

These must be converted into the sensor "wanted states"( by straight
forward combination logic, a few gates) which are:

NESW
0100 Tool 1
0110 Tool 2
0010
0011
0001
1001
1000
1100

Going by what you said.

You "AND" each sensor input with these values and then "AND" them
all together before inverting (NAND) and wire to the motor amp.
i.e. The motor will run when the sensors do not match the index
position.

On power up the motor will do one of two things, either turn until
it goes to position 1 or it might be at position 1 already. When an
index pulse comes in the counter increments and the output is
converted to the wanted states on the sensors, the motor turns on
until these states are correct.

Now I don't know if this is enough, if the motor needs to be pulled
back to lock with the ratchet then that makes things more difficult
or if the sensors are built with an overshoot built in so that you
then reverse until the condition is false again I don't know as the
info on the ratchet etc is sketchy.

Could you just have two motor states, on and lightly reversed (with
current limit).

Have you looked at the origional circuit to try and gleam exactly
what it did?

Graham

p.s. I am rusty on logic and know less about tool changers :)