In this section, I will show examples of basic stepper motor translation circuits. Not all of these examples have been tested, so be sure to prototype the circuit before soldering anything.
Figure 8.1 illustrates the simplest solution to generating a one-phase drive sequence. For unipolar stepper motors, the circuit in Figure 2.1, or for bipolar stepper motors, the circuit in Figure 6.1 can be connected to the 4 outputs of this circuit to provide a complete translator + driver solution. This circuit is limited in that it cannot reverse the direction of the motor. This circuit would be most useful in applications where the motor does not need to change directions.
Figure 9.1 is an translator for two-phase operation. I have seen this circuit many places, but I believe it originated from The Robot Builders' Bonanza book, by Gordon McComb. I have used this circuit in the past and seem to recall that it had a problem. This may not be the case but I think when you reverse direction and continue stepping, the motor will advance 1 more step in the previous direction it was going before responding. As always, prototype this circuit to be sure it will work for your application before you build anything with it.
There are several standard stepper motor translation circuits which use discrete logic ICs. Below you will find yet another one of these. The circuit in Figure 10.1 has not been tested but theoretically should work without problems.