Electrical circuitry for vehicular refrigerating systems

Claim 2

In an electrical circuit of the type described, separate sources of alternating current and direct current voltage, and an electrical device energizable effectively only by direct current, a relay electrically connected between said device and said direct current source and energized by the latter to complete a holding subcircuit for the device from said source, as well as a direct current energizing circuit through said device, and rectifying means electrically connected in a circuit also including said relay between said alternating current source and said device to energize the latter under a steady current from the alternating current source, as an alternative to energization from the direct current source.

Claim 3

The circuit of claim 1, and further comprising transformer means electrically connected between said alternating current source and said rectifying means.

Claim 4

The circuit of claim 1, and further comprising a rectifier element electrically connected between said direct curreNt source and the relay to prevent direct current flow to the latter when the device is energized from the alternating current source.

Claim 5

The circuit of claim 2, and further comprising a rectifier element electrically connected between said direct current source and the relay to prevent direct current flow to the latter when the device is energized from the alternating current source.

Claim 6

The circuit of claim 2, in which said alternating current source is a relatively high voltage alternating current line, said direct current source being a battery of relatively low voltage rating.

Claim 7

The circuit of claim 3, in which said alternating current source is a relatively high voltage alternating current line, said direct current source being a battery of relatively low voltage rating.

Claim 8

The circuit of claim 4, in which said alternating current source is a relatively high voltage alternating current line, said direct current source being a battery of relatively low voltage rating.

Claim 9

An electrical circuit comprising a direct current motor, separate sources of alternating current and direct current voltage of substantially different voltage rating, one of said sources being a battery and the other source being a relatively high voltage alternating current line into which the subject circuit may be plugged, control switches wired in series with the battery, a relay connected in series with said switches and energized by direct current flow through the coil of the relay to complete a direct current holding subcircuit for said motor, as well as a motor energizing subcircuit through the armature of the relay to the motor, a stepdown voltage transformer having its primary electrically supplied by said alternating current source, rectifying means electrically connected to the secondary of said transformer and to said motor to complete a stepped-down and rectified electrical motor energizing circuit as an alternative to the battery-supplied circuitry to the motor.

Claim 10

An electrical circuit comprising a direct current motor, separate sources of alternating current and direct current voltage of substantially different voltage rating, one of said sources being a battery and the other source being a relatively high voltage alternating current line into which the subject circuit may be plugged, control switches wired in series with the battery, a relay connected in series with said switches and energized by direct current flow through the coil of the relay to complete a direct current holding subcircuit for said motor, as well as a motor energizing subcircuit through the armature of the relay to the motor, a stepdown voltage transformer having its primary electrically supplied by said alternating current source, rectifying means electrically connected to the secondary of said transformer and to said motor to complete a stepped-down and rectified electrical motor energizing circuit as an alternative to the battery-supplied circuitry to the motor.

Claim 11

The circuit of claim 8, and further comprising a rectifier element electrically connected between said battery and the relay to prevent a flow of direct current to said motor in opposition to the stepped down and rectified current.

Claim 12

The circuit of claim 8, in which said rectifying means comprises diodes connected to opposite terminals of the transformer secondary, a center tap of said secondary being electrically connected to a terminal of the relay and another terminal of the relay being connected to the motor.

Claim 13

The circuit of claim 9, in which said rectifying means comprises diodes connected to opposite terminals of the transformer secondary, a center tap of said secondary being electrically connected to a terminal of the relay and another terminal of the relay being connected to the motor.

Claim 14

The circuit of claim 1, and further comprising at least one control switch connected in series with said relay in said holding circuit.

Claim 15

The circuit of claim 2, and further comprising at least one control switch connected in series with said relay in said holding circuit.

Claim 16

The circuit of claim 3, and further comprising at least one control switch connected in series with said relay in said holding circuit.

Claim 17

The circuit of claim 12, in said control switch is a thermostatic one, and further comprising one manually operated switch connected in series with said relay and said control switch in said holding circuit.

Claim 18

The circuit of claim 13, in said control switch is a thermostatic one, and further comprising at least one manually operated switch connected in series with said relay and said control switch in said holding circuit.

Claim 19

The circuit of claim 14, in said control switch is a thermostatic one, and further comprising at least one manually operated switch connected in series with said relay and said control switch in said holding circuit.