Step drive principle-1

Stepper drives can be divided into two parts, one is a ring distributor and the other part is power amplification. Ring distributor: If you receive 3 kinds of signals: pulse signal, direction signal, offline signal. The pulse signal is then distributed to control the corresponding transistor on-on of the power amplifier, and then the coil of the stepper motor is charged.

From here we can see that the stepper motor to run then must input pulse, if there is no pulse, the stepper motor is not moving, so we need a driver to power the windings of the stepper motor in turn.

Direction Signal: To control the phase sequence of AB power, A-B clockwise, B-A counterclockwise Offline signal: stepper motor stop, AB coil has a phase of electricity, the function of the power so that the rotor locked, so that the rotor can not move, need to take to transfer the rotor, need to give the offline signal, so that the AB phase winding completely power off, the rotor is in a free rotation state.

Connection between stepper motor, stepper driver and PLC: Step perusing driver first external DC power supply 24 to 28V, one end to step per step per step motor, the other end as input signal is the control signal, stepper motor to accept the structure of external signal is the use of photoelectric isolation, such as: PLC pulse signal sent to the inside of the drive,

We want to make PLC pulse only need to make Y0 constantly connected and cut off can be produced. When Y0 is on, the current flows in from the CP plus, through the current-limiting resistor, diode, and then through the CP-, and then back to the negative end of the power supply through the COM end, thus forming a loop. In this case the light-emitting diode is on, the transistor will also be on will produce a high level 1, if the cut-off will produce a low level 0. This way, when Y0 is constantly turned on and cut off, and the circuit allows the pulse to be sent from the external device to the driver. The ring distributor then receives the pulse and distributes the pulse signal. The windings that control the stepper motor are electrically charged in turn. So the stepper motor must have a pulse when it rotates, and if there is no pulse, the stepper motor will be in a stopped state. The same is true of directional signals as decoupling signals.