Circuit arrangement for cyclic supply

DETAILED DESCRIPTION We claim: 1.
A control circuit for controlling an electromagnetic load in accordance with an input signal, the control circuit comprising: a frequency/voltrage transformer for receiving a control signal of a given frequency; an integrator, an input of the integrator being coupled to an output of the frequency/voltage transformer and an output signal of the integrator being indicative of the deviation of the frequency of the control signal from a predetermined value; comparison means, a first input of the comparison means receiving a first current signal indicative of a current through the load, a second input of the comparison means receiving the input signal, the comparison means generating the control signal in accordance with the comparison of the first current signal and the input signal, and the comparison means having a hysteresis which can be altered as a function of the output signal of the integrator so that the control signal has a frequency that corresponds substantially to the predetermined value; and a switching device coupled to the electromagnetic load and controlled by the control signal, thereby controlling the electromagnetic load.
2.
The control circuit according to claim 1, wherein the comparison means includes a comparator.
3.
The control circuit according to cliam 1, wherein the comparison means includes a trigger device.
4.
The control circuit according to cliam 3, wherein the trigger device includes a Schmitt trigger.
5.
The control circuit according to claim 1, wherein the frequency/voltage transformer includes a comparator.




Description:
PRIOR ART The invention relates to a circuit configuration for the synchronized supply of an electromagnetic user with regulation which is acted upon by a control signal representing the difference between the instantaneous signal at the user and a predeterminable reference signal.
This type of a circuit configuration is known e.
g.
from the U.
S.
Pat.
No.
4,452,210 and comprises a driver circuit for an injection valve of an internal-combustion engine