Current regulator

Details Current regulator Current regulator

1991-05-01

1992-12-22

Voeltz, Emanuel T.

Electricity: power supply or regulation systems

Output level responsive

Using a three or more terminal semiconductive device as the...

323282, 323351, G05F 1565

Patent

active

051736551

DESCRIPTION:

BRIEF SUMMARY
FIELD OF THE INVENTION

The present invention relates generally to a current regulator and, more particularly, to a transistorized regulator circuit which incorporates a comparator.


BACKGROUND

Current regulators for higher currents, whose output current is a function of an input quantity, are hard to control in respect to their dynamic stability because of the great steepness and the resulting high amplifications of open collector stages. High-frequency oscillations over the entire range of the operating current under all conditions of use are hard to prevent, in particular in connection with rapidly operating regulators, which are intended for universal use and as a consequence may be connected with the operational voltage, the control device and the consumer via cable harnesses of different length.
Because the transition frequency of transistors is reduced with lowering current density, it would be required to make the upper limit frequency of the positive feedback loop for the range located in the vicinity of the output current "zero" lower than for the range of higher currents However, variable limit frequencies require increased circuit outlay.
From the textbook by Winfried Oppelt, "Kleines Handbuch technischer Regelvorgaenge" [Brief Manual of Technical Regulation Processes], published by Verlag Chemie GmbH, Weinheim [Fed. Rep. of Germany], Vol. 5, 1972, as well as from French patent document FR-A-2 336 841, non-linear regulators are already known, whose describing function or transfer function has a dead zone in the range around the zero point.
From German patent document DE-A-1 513 127 a circuit arrangement for avoiding error functions of an electrical main circuit is furthermore known, which prevents the switching on of a main circuit prior to the required supply voltage having been reached. For this purpose a control and amplifier unit is placed upstream of the main circuit which only switches on the main circuit after a required supply voltage has been reached. From the article by Claude Boisard entitled "Un CI regulateur de vitesse pour moteur a courant continu a aimant permanent" [A Printed Circuit Speed Control for a Constant Current Motor with a Permanent Magnet] in the magazine "Electronique Industrielle et Microelectronique (EMI)", No. 162 of Oct. 15, 1972, pp. 57 to 60, a speed control for an electric motor with a permanent magnet is furthermore known, which contains in the motor excitation circuit an npn-end stage transistor whose emitter is connected to a negative supply voltage. In this case an operational amplifier is placed upstream of the npn-end stage transistor for switching the npn-end stage transistor on and off as a function of a control quantity and a reference voltage.
Furthermore, from FIG. 4 of German Letters Patent DE-PS 21 47 179 and corresponding U.S. Pat. No. 4,028,564, a current regulator in accordance with the species of the main claim is known, identified there as a controllable current source, which is designed for low output currents.


OBJECT, ATTAINMENT OF OBJECT AND ADVANTAGES OF THE INVENTION

It is the object of the invention to screen out the low currents in a current regulator and designed for high currents.
In this connection, it is particularly advantageous if the output of the comparator is connected with the output of the operational amplifier via the collector-base-section of an auxiliary npn transistor whose emitter is connected to ground.
In a further development of the invention, the comparator may be a comparator with hysteresis. By means of this, it is attained that the output current of the current regulator, in the current consuming range with falling input voltage, is switched off at a lower value of the input voltage than that at which it is switched on.


DRAWINGS

The invention will be described by means of FIGS. 1 and 2.
FIG. 1 shows the transfer characteristic curve, and
FIG. 2 is a block diagram of the current regulator.


DESCRIPTION OF THE INVENTION

The transfer characteristic curve 13 of the output current I of a current regulator fo

REFERENCES:
patent: 4028564 (1977-06-01), Streit et al.
patent: 4712169 (1987-12-01), Albach
patent: 4849683 (1989-07-01), Flolid

Affiliated with

Also associated with

Rating

Current regulator does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Current regulator, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Current regulator will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-976584