Precision constant current control with automatic compensation

Claim 2

A circuit having an alternating current input, a synchronous switch means in series with the input and having a control coil to control the energy throughput of said synchronous switch means; characterized in that the output of said circuit is at a predetermined constant current level to a load; wherein the rate of alternating current input through said synchronous switch means is controlled by said control coil, and where the current through said control coil is sensed and controlled so as to maintain the ampere-turns ratio of said control coil at a constant value; whereby said output current to a load is maintained at said predetermined constant current level irrespective of the internal resistance characteristic of said control coil, or changes of said resistance characteristics; and wherein current through said control coil is sensed by way of a current probe in series with said control coil, the output of said current probe being fed to a constant current sensing and output adjusting circuit whose output controls a regulator for said control coil, whereby the amount of current flowing through said control coil may be maintained constant.

Claim 3

The circuit fo claim 1, where said controlled constant current output current is an alternating current.

Claim 4

The circuit of claim 2, where regulation of the current in said control coil is by means of a shunt regulator means connected in parallel with said control coil.

Claim 5

The circuit of claim 2, where regulation of the current in said control coil is by means of a series regulator means connected in series with said control coil.

Claim 6

The circuit of claim 1, further comprising rectifier means at said input with said synchronous switch means, whereby said controlled constant current output current is a direct current.

Claim 7

The circuit of claim 5, where regulation of the current in said control coil is by means of a shunt regulator means connected in parallel with said control coil.

Claim 8

The circuit of claim 6, as a battery charger connected to a load of at least one battery.

Claim 9

The circuit of claim 6, as a battery forming and charging circuit connected to a load of at least one battery.

Claim 10

The circuit of claim 5, where regulation of the current in said control coil is by means of a series regulator means connected in series with said control coil.

Claim 11

The circuit of claim 5, where said constant current sensing and output adjusting circuit is initially controlled by a disconnect latch and soft walk-in circuit; whereby when said load is first connected to the output of said circuit, the output current gradually increases to said predetermined constant level.

Claim 12

The circuit of claim 1, where there is a discontinuity alarm sensing the output of said circuit; so that if a discontinuity between the output of the circuit and the load or within the load is sensed and the output current reduces to zero, then the current through said control coil will be reduced to zero.

Claim 13

The circuit of claim 1, where current limiting means is in series with said control coil.

Claim 14

A circuit having an alternating current input, a synchronous switch means in series with the input and having a control coil to control the energy throughput of said synchronous switch means; characterized in that the output of said circuit is at a predetermined constant current level to a load; wherein the rate of alternating current input through said synchronous switch means is controlled by said control coil, and where the current through said control coil is sensed and controlled so as to maintain the ampere-turns ratio of said control coil at a constant value; whereby said output current to a load is maintained at said predetermined constant current level irrespective of the internal resistance characteristic of said control coil, or changes of said resistance characteristics; wherein current through said control coil is sensed by way of a current probe in series with said control coil, the output of said current probe being fed to a constant current sensing and output adjusting circuit whose output controls a regulator for said control coil, whereby the amount of current flowing through said control coil may be maintained constant; and wherein said constant current sensing and output adjusting circuit is initially controlled by a disconnect latch and soft walk-in circuit; whereby when said load is first connected to the output of said circuit, the output current gradually increases to said predetermined constant level.

Claim 15

A circuit having an alternating current input, a synchronous switch means in series with the input and having a control coil to control the energy throughput of said synchronous switch means; characterized in that the output of said circuit is at a predetermined constant current level to a load; wherein the rate of alternating current input through said synchronous switch means is controlled by said control coil, and where the current through said control coil is sensed and controlled so as to maintain the ampere-turns ratio of said control coil at a constant value; whereby said output current to a load is maintained at said predetermined constant current level irrespective of the internal resistance characteristic of said control coil, or changes of said resistance characteristics; wherein current through said control coil is sensed by way of a current probe in series with said control coil, the output of said current probe being fed to a constant current sensing and output adjusting circuit whose output controls a regulator for said control coil, whereby the amount of current flowing through said control coil may be maintained constant; and wherein said constant current sensing and output adjusting circuit is initially controlled by a disconnect latch and soft walk-in circuit; whereby when said load is first connected to the output of said circuit, the output current gradually increases to said predetermined constant level.