Danfoss Compressors Gmbh

Claus Schmidt

Hans Peter Kristensen

Rune Thomsen

Ole Schebel Bachmann

Mads Andersen

A method and a control unit () for controlling a supply of power to an electrical circuit comprising a switch (). An output voltage of a first power source (), which is connected to the circuit, is measured and compared to a predefined threshold voltage. If the measured voltage is smaller than the threshold value it is determined that the switch () is in a closed state, and if the voltage is larger than the threshold value it is determined that the switch () is in an open state. The supply of power is controlled in accordance with the open/closed state of the switch (). Preferably, the electrical circuit is connected to a second power source () when the switch () is in a closed state. Power is conserved while it is ensured that sufficient power is available when needed. The invention is very suitable for supplying power to a lamp () positioned inside a refrigeration compartment (), especially when the system is battery powered.

Intelligent lighting supply

Motor start circuit for an induction motor-with a main winding and an auxiliary winding having two end connections supplied with current via current supply connections, and with a start circuit device serving the purpose of stopping the current flow through the auxiliary winding after the start of the motor, and being connected via a conductor to a control device connected between the current supply connections, and with a preset timer device interacting with the start circuit device to stop the current flow through the auxiliary winding, as soon as a predetermined period after the start of the current flow has lapsed. With the purpose of optimizing the motor start circuit, a voltage presetting device, with which a predetermined voltage value can be set, the start circuit device being disconnected if this value is exceeded, and a period duration presetting device, are connected to or integrated in the control device.

Motor start circuit

Motor start circuit for an induction motor, particularly a single-phase AC induction motor, with a main winding () and an auxiliary winding (), which are supplied with current, particularly alternating current, via current supply connections (), and with a start switching device () serving the purpose of interrupting the current flow through the auxiliary winding () after the start of the motor, the start switching device () being connected to a control device () via a connector (), the control device () being connected between the current supply connections (), and with a winding protection switch (), which is normally closed and which opens on the occurrence of a fault. The invention is characterized in that the control device () is connected to the winding protection switch () via at least one further connector (), preferably via at least one further connector () and the auxiliary winding ().

The invention concerns a motor starter circuit for an induction motor, particularly a single-phase AC induction motor, with a main winding () and an auxiliary winding () supplied with current, particularly AC, via current supply connections (), and with a starter switch arrangement (), which serves the purpose of interrupting the current flow through the auxiliary winding () after the start of the motor, the starter switch arrangement () interacting with a measuring arrangement serving the purpose of measuring the voltage across the auxiliary winding (). In order to optimise the motor starter circuit with regard to operation safety, a protection fuse () and a protection switch arrangement () are connected in series between the current supply connections () so that, when the protection switch arrangement () is closed, the current flows in such a manner through the protection switch arrangement () and the protection fuse () that the protection fuse () is triggered to interrupt the current flow.

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Odense NV, Denmark

Claus Schmidt