The direct current generator current detection circuit
Technical field
The utility model relates to the DC MOTOR CONTROL field, relates in particular to the direct current generator current detection circuit.
Background technology
At the requirement that mechanical separator speed detects, many detection modes have been designed in the prior art.Wherein the rotating speed of direct current generator just detects and has adopted detection techniques such as magnetic induction, photoelectric sensing, high-side current sampling to detect rotating speed by the electric current that detects direct current generator.This class technology utilization of magnetic induction, photoelectric sensing is based on sensor technology, therefore sensor must be installed in the synchronous operated parts of direct current generator on, thereby obtain the direct current generator electric current.In the work, the magnetic inductor reaction velocity is slow, and photoelectric sensor is subject to that dust disturbs and easily along bad, so testing instability after the utilization magnetic induction, photoelectric sense technology is subject to external interference.High-side current sample detecting technology is to place between power supply and the load detecting resistance, because the ground connection of controller is floating-point, so the suffered interference of high-side current sample detecting is big.
The utility model content
The technical problems to be solved in the utility model provides a kind of direct current generator current detection circuit, and Speedless sensor is simple in structure, and work is sensitive stable.
For solving the problems of the technologies described above, the utility model adopts following technical scheme: the direct current generator current detection circuit is serially connected with the noninductive resistance R1 of the direct current generator working current signal that is used to sample at the low side of the IGBT that is used to control direct current generator, the current signal that obtains on the described noninductive resistance R1 through sampling keep, computing amplify after Input Control Element.
The utility model adopts technique scheme, and the direct current generator current detection circuit is simple in structure, and reaction velocity is fast, not disturbed by dust, working stability, and maintenance cost is low.
Description of drawings
Below in conjunction with the drawings and specific embodiments the utility model is further specified.
Fig. 1 is the schematic diagram of utility model direct current generator current detection circuit.
Embodiment
As shown in Figure 1, be in series with IGBT and noninductive resistance R1 on the earth return circuit of direct current generator, the G utmost point of IGBT is connected with drive circuit of DC motor, and the E utmost point of IGBT is connected with noninductive resistance R1.Produce very little pressure and incite somebody to action when direct current generator is worked on noninductive resistance R1, the backlash current that produces when this voltage signal is worked with direct current generator is relevant.Be this voltage signal of sampling, the E of IGBT extremely in parallel high frequency sampling switch IC2, the controlled unit controls of this high frequency sampling switch, the signal after the sampling amplifies the back Input Control Element through the operational amplification circuit that comprises operational amplifier IC3.Draw corresponding motor speed by the software operational analysis again.