With the rapid development of industry, explosion-proof electric drums are widely used in various fields, including basically all mechanical industries. Limiting current is also important when using such devices. The following is a detailed introduction to the current limit of explosion-proof electric drum.
1.The external inverter bridge of the explosion-proof electric drum is grounded through a resistor Rs used for current sampling, and the sampled voltage is input to the current detection comparator. Set a 100mV reference voltage as the current limiting reference at the inverting input of the comparator.
2.During the rise time of the sawtooth wave in the oscillator, if the current is too high, the device is prone to flipping, causing the Rs trigger below to reset, turn off the drive output, and limit the continuous increase of current. Sawtooth wave descent time, trigger reset, turn on drive output.
3. Explosion proof electric drum uses this cycle by cycle current comparison to achieve current limiting. If a larger current is allowed for Imax, the sampling resistor is selected according to the following formula: RS=0.1/Imax. To avoid current detection errors caused by commutation spikes, an RC low-pass filter can be set before input.
The working principle and application characteristics of this device are the same as those of ordinary DC motors, but the composition is different. The commutation circuit consists of two parts: drive and control, which are not easy to separate. Especially for low-power circuits, they are often integrated into a single ASIC. If you want to reverse this device, you first need to know that explosion-proof electric rollers are different from ordinary induction motors. You cannot directly replace the winding wire, but you also need to replace the Hall wire. If switching the logic sequence directly on the driver, the general measure is to short-circuit the F/R and low level.
In the long-term use of explosion-proof electric drum, it is necessary to limit its current to ensure the long-term stable operation of the equipment. For the convenience of everyone, this article provides detailed current limit standards, which can be used to standardize the built-in devices.
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