A method for starting or anti-stalling of a DC brushed motor

Abstract

In the method for starting or anti-stalling of a DC brush motor according to the present invention, the operating current is modulated by the PWM control module on the basis of the traditional overcurrent protection period, so that during the first half cycle of each current slow decay, There is a load current, and the load current is stable at the modulation current threshold, that is, it can still provide a safe and constant starting torque for the DC brush motor; during the half-cycle process after the rapid decay of each current, PWM modulation is not performed, Let the brushed DC motor lose the driving torque and coast freely; that is, to realize the cyclic action of "...start-glide-start-glide-start..." of the brushed DC motor. The two modes are switched at intervals, so that the brushed DC motor winding coil Jitter, and then generate rotational inertia. On the one hand, the rotational inertia weakens the static torque of the DC brush motor, and on the other hand, it adds to the constant starting torque of the DC brush motor, and finally realizes the safe start of the DC brush motor.

Description

technical field [0001] The invention relates to the driving technology of a DC brush motor, in particular to a method for starting or anti-stalling of the DC brush motor. Background technique [0002] like figure 1 Shown is the schematic diagram of the H-bridge drive circuit of the H-bridge driver to drive the DC brush motor. The DC brush motor is simplified as an inductive load LR. In the H-bridge drive circuit, the first high-side PMOS switch M1 and the third low The drain of the side NMOS switch M3 is connected to the first node A, the second high-side PMOS switch M2 and the fourth low-side NMOS switch M4 are connected to the second node B, and one end of the inductive load is connected to the first node A , the other end is connected to the second node B, wherein D1, D2, D3, D4 are the first high-side PMOS switch M1, the second high-side PMOS switch M2, the third low-side NMOS switch M3 and the fourth low-side The parasitic diode of the NMOS switch M4. remove figure ...

AI Technical Summary

Problems solved by technology

When the DC brush motor starts or stalls, because the winding coil is static, it needs to overcome the static torque of the winding coil to do work without the reverse electromotive force to suppress the winding coil current. At this time, the DC brush motor winding coil The starting current or locked-rotor current Iload is extremely large, at least 1.5 times the rated operating current, and it is very easy to trigger the overcurrent protection circuit of the H-bridge driver. Once the traditional overcurrent protection circuit of the H-bridge driver is triggered, it is easy to enter the above-mentioned The traditional over-current protection cycle, and the traditional over-current protection makes the DC brushed motor more difficult to start, if the selection of the H-bridge driver, the DC brushed motor model and the drag load do not match, the over-current detection of the traditional over-current protection circuit And the high resistance protection state will loop infinitely, that is, it has entered an infinite loop, and the brushed DC motor is blocked and cannot start by itself.

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