IC driver motor
Schema drivers for electric motors are a great, compact solution to control this kind of circuit. Available in our online store drivers engine – the chip allows you to manage a wide range of DC motors, and stepper motors. Some of them have added features such as the ability to control the motor current, due to the application of speed adjustment time of the pulse.
Control signal with a variable fill
Some of the services in our Internet-store of the motors ' driver – ICS are able to modulate the operation of the H bridge in the system by using the flow variable fill, so-called PWM (eng. pulse width modulation – modulation of the pulse duration). Such processes resemble regular rectangular wave. The only difference is that the time when the signal is in high condition, should not be equal to the time when the output has a low. Ratio of time when the signal is in the high state for the entire period of the input signal, is called a filling run. For level 100% the signal is constantly in a high state, and 0% are low. The frequency of the PWM signal, as a rule, significantly higher than the rate of change of engine speed in this device.
Effective current control through the PWM signal
Through the use of modulated signals with a variable filling of the motors ' driver chip can modulate the average current flowing through the motor windings. Modulation-PWM modulation, the zero-jedynkową, that is, one that has only two discrete States – high and low. In the high state, the motor current flows, and low not. Modulation does not change the value of the current transient, which is dependent on voltage and winding resistance. If uśrednimy the current flowing through the motor during the entire period of the modulating signal, the average will be equal katalogowemu motor current pomnożonemu by the pulse. If it is equal, for example, 50%, then the average current flowing through the motor equal to half the nominal current.
The main parameters of selection of drivers
Picking up the motor driver chip for our application and for a particular engine, we must pay attention to the number of parameters. The two most important related to the requirements of the engine relative to the power is the voltage and the current flowing through the motor. Both of these parameters can be read from the data sheet of the motor or its nameplate. The maximum allowable voltage and current of the motor driver must be greater than the values required to power your engine. Otherwise we run the risk of a catastrophic accident, which may cause system damage. If to control the operation of the engine, to use want to run PWM, you should make sure that this chip has this feature, and that the maximum frequency of the modulating signal in the system longer stroke frequency PWM, we want to use.