Circuit arrangement for monitoring the current supply of an elec

Details Circuit arrangement for monitoring the current supply of an elec Circuit arrangement for monitoring the current supply of an elec

1986-08-18

1987-12-29

Zazworsky, John

Electrical transmission or interconnection systems

Nonlinear reactor systems

Parametrons

307296R, 307358, 307592, 307597, 361 90, H03K 524, G01R 19165

Patent

active

047163720

DESCRIPTION:

BRIEF SUMMARY
STATE OF THE ART

The invention relates to a circuit arrangement for monitoring the current supply of an electric consumer, in particular of a microcomputer on a mobile data carrier with inductive energy transmission, as defined by the preamble to claim 1.
In mobile data carriers, as embodied by workpiece carriers revolving in automatic transfer lines or assembly lines, the supply energy for the switching circuits disposed on the data carrier are transmitted inductively from processing and control stations arranged along the transfer or assembly lines, specifically by intermittent inductive coupling of transformer coils, present in the fixed station and on the data carrier, at the moment the data carrier travels through the fixed station. This produces an operating voltage for the data carrier, which is dependent on many variables, such as the distance between the transformer coils and the data carrier on the one hand and the fixed station on the other, the speed of the data carrier, and the like and therefore varies within wide limits. However, the microcomputer provided on the data carrier for controlling data transmission to the fixed station and for data processing in the data carrier requires a constant supply voltage, so that it has to be switched on and off in accordance with voltage, and an accurate power-up and power-down sequence must be adhered to.
A supply voltage monitor is also known (Texas Instruments component TL 7702) that monitors the magnitude of a stabilized supply voltage, which can be picked up at the output of a voltage regulator (component 78 L 05), and when a rated value is attained generates a startup pulse for a consumer, this pulse being present with a delay time until the supply voltage drops below the rated value. Because of the imprecision of the tolerance of the stabilized supply voltage, the rated value is dimensioned to be lower than the stabilized supply voltage, so that with the aid of the delay time, the startup pulse triggers the switching on of the consumer approximately when the supply voltage is attained.
The known voltage monitor, which is intended for power packs, cannot be used whenever the rise speed of the input voltage of the voltage regulator differs greatly from one instance to another, as happens with the current supply of mobile data carriers, because when the inductively transmitted operating voltage is dependent on the greatly varying speed of the data carrier as it travels past the fixed station. In that case, it is impossible to fix a favorable value for the delay time of the startup pulse. Moreover, when the supply voltage drops, the known voltage monitor switches only after the stable state of the supply voltage has already been left behind. There is then an inadequate reserve for the power-down sequence. In general, it is not possible with the known voltage monitor to exert any influence on power reserves.


ADVANTAGES OF THE INVENTION

The circuit arrangement of the invention has the advantage that the startup signal for the current consumer is triggered precisely upon attainment of the stabilized supply voltage, and under no circumstances beforehand, and that upon shutdown the power reserves are fully exhausted, because the shutdown signal for the current consumer is triggered whenever the current is still just adequate for supplying the consumer with a constant supply voltage. Tolerances of the voltage regulator, the current drawn by the circuit arrangement and the rise speed of the operating voltage no longer have any influence at all. By means of comparator dimensioning, either an immediate startup of the consumer or a delayed startup of the consumer is performed only when excess power is available. By picking up the reference voltage at the regulator output, the stability of the reference voltage is assured. Forming the threshold at the regulator input provides a pre-stabilization of the voltage regulator, so that standard deviations, and deviations of the supply voltage from its constant value dictated thereby, are lessened.
The comparator is

REFERENCES:
patent: 4428020 (1984-01-01), Blanchard, Jr.
patent: 4536667 (1985-08-01), Masuda
patent: 4594517 (1986-06-01), Cohen et al.

Affiliated with

Also associated with

Rating

Circuit arrangement for monitoring the current supply of an elec does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Circuit arrangement for monitoring the current supply of an elec, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Circuit arrangement for monitoring the current supply of an elec will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-464955