H bridge power drive circuit can be applied to the stepping motor, ac motor, dc motor driver, etc. Permanent magnet stepper motor or hybrid stepping motor excitation winding must be in double polarity power supply, that is to say, winding sometimes need to forward current, sometimes need to reverse current, the winding H bridge driving power supply. Based on the two-phase hybrid stepping motor drive as an example to design the H bridge driving circuit. Four switch K1 and K4, K2 and K3 control signal respectively. A, b, when the control signal to switch K1, K4 closed, K2, K3 is off, the current flow in the coil is shown in figure 1 (a), when the control signal to switch K2, K3, K1, K4 disconnected, the current flow in the coil is shown in figure 1 (b)Shown below. Four diode VD1, VD2, VD3, VD4 fly-wheel diode, their role is: when the K1, K4 switch controlled by closing to opening, due to the coil winding of current cannot mutation on AB, still need to be according to the original direction of current flow,The A and B), this time by VD3, VD2 to provide circuit. Therefore, the current K1, K4 shut off moment by the ground - VD3 - coil winding AB - VD2 - power + v form current loop. Similarly, in figure 1 (b)When the switch K2, K3 shut off moment, by the diode VD4, VD1 provide coil winding stream, current loop is to BA - VD4 - coil winding - VD1 - power + v. Stepper motor drives, realizing the function of the switch components in practical circuit adopts power MOSFET tube. H bridge by stepper motor drive circuit, the current flow in the windings are two completely opposite direction. Promote the signal logic level should make the diagonal transistor cannot at the same time conduction, lest cause high and low pressure pipe straight through. In addition, the stepping motor's winding is inductive load, when the electricity, with the increase of motor operating frequency, and transition time constant, often makes the winding current and haven't had time to reach steady state value is cut off, the average current decreases, the output torque, high when the driving frequency in due time will have blocked or out-of-step phenomenon. Stepper motor driver, therefore, in addition to the design of the motor as far as possible to reduce the winding inductance, and take measures of the drive power, namely improve the front and back along the gradient of the conduction phase current in order to improve the performance of the motor running. The defect of stepper motor is a high frequency output, low-frequency oscillation, the performance of the stepper motor, besides the inherent performance of the motor drives the driving power is directly affect the characteristics of the motor. To improve the frequency characteristics of stepping motor, we must improve the power supply voltage. the main products: stepper motor, brushless motor, servo motor, stepping motor drive, brake motor, linear motor and other kinds of models of the stepper motor, welcome to inquire. Telephone:
