JPS63197206A - Current control circuit - Google Patents

Abstract

PURPOSE:To avoid the consumption of electric power as well as the generation of heat and noises by forming a current control circuit with use of a D/A converter and a constant current control circuit so that the current value can be varied dynamically by a program. CONSTITUTION:When a control signal 6 of a certain level is applied to a D/A converter 2, the reference voltage signal 7 corresponding to the signal 6 is applied to a constant current control circuit 3. The circuit 3 delivers a driver control signal 8 so that the signal 7 has the same level as that of a current detecting signal 9. A driver circuit 4 drives a motor 5 based on the signal 8 and detects the value of the current flowed to the motor 5 for output of the signal 9. Thus the current flowing to the motor 5 can be changed with change of the value of the signal 6 received from the microprocessor 1. Thus the signal 6 of the converter 2 is controlled by a program and therefore the current flowing to the motor 5 is freely changed.

Description

TECHNICAL FIELD The present invention relates to a current control circuit, and more particularly to a current control circuit using a microprocessor.

Prior Art Conventionally, the current ill 111 circuit was composed of only a constant current interrogation circuit. For this reason, it is not possible to dynamically vary the set current from a microprocessor or the like, and it is necessary to always supply the maximum current required by the circuit. For this reason, more current than necessary is passed during a certain period of time, resulting in disadvantages such as extra power consumption, extra heat generation, and extra noise generation.

Therefore, an object of the present invention is to provide a current control circuit that does not allow more current to flow than necessary.

Structure of the Invention According to the present invention, a microprocessor and a D converting a control signal from the microprocessor into an analog signal are provided.
Δ] converter and a constant current control circuit that performs constant current control based on the analog control signal from the OA converter.

Embodiment Next, the present invention will be explained in more detail with reference to the drawings showing an embodiment of the present invention.

Referring to FIG. 1, in one embodiment of the present invention, a microprocessor 1 to DA (digital analog)
Converter control] signal 6 is fed to the input of DΔ converter 2. The output signal of the DA converter 2 is supplied as a reference voltage signal 7 to the constant current control circuit 3. A driver control signal 8 is supplied from the constant current control circuit 3 to a driver circuit 4, and the driver circuit 4 drives the motor 5. Further, the driver circuit 4 supplies a current detection signal 9 to the constant current control circuit 3.

A question signal 6 of a certain value is sent from the microprocessor 1 to DA.
By applying it to the converter 2, a reference voltage 7 corresponding to this control signal 6 is applied to the constant current 01111 circuit 3. The constant current control circuit 3 outputs the driver control signal 8 so that the voltage values of the reference voltage signal 7 and the current detection signal 9 are equal. Driver circuit 4 is driver control signal @8
The motor 5 is driven based on the current value, the current value flowing through the motor 5 is detected, and a current detection signal 9 is output.

By changing the value of the digital control signal 6 from the microprocessor 1, the current flowing to the motor 5 can be changed. That is, by dynamically manipulating the value of the OA converter control signal 6 using a program, the current flowing to the motor 5 can be freely changed.

In this example, the case of controlling a motor was shown, but
The same applies to items other than motors such as lamps. Furthermore, the range of current that can be varied can be freely changed by increasing or decreasing the number of bits of the DA converter control signal 6 or by changing the configuration of the DA converter 2.

As explained above, the present invention configures a current control circuit with a DA converter and a constant current υ control circuit, so that the current value can be dynamically varied by a program. The current value can be set to a current value of 1, which has the effect of preventing excessive power consumption, excessive heat generation, and excessive noise generation.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of one embodiment of the present invention. Explanation of symbols of main parts 1...Microprocessor 2...DA converter 3... Constant current control circuit 4... Driver circuit 5...Motor

Claims (1)

[Claims] a microprocessor; a DA converter that converts a control signal from the microprocessor into an analog signal;
A current control circuit comprising: a constant current control circuit that performs constant current control based on an analog control signal from the DA converter.