Mitel Knowledge Corporation

Mitel Networks Corporation

Christopher Graham Lucas

Scott Richard Burton

A circuit provides a secondary output voltage from an input voltage. The circuit includes power supply circuitry for creating an unregulated DC bus voltage line and a regulator circuit connected to the DC bus voltage line for controlling a first switch in series with a transformer winding. The control circuit samples an output voltage to control the output voltage by cycling the first switch. The circuit further includes a pulse generator circuit connected to the regulator circuit for controlling start and stop cycles of the regulator circuit and a comparator circuit connected to the pulse generator circuit for monitoring the secondary output voltage and for disabling the pulse generator circuit during normal operation of the power supply circuit.

Power supply start up circuit

The present invention is a battery transfer circuit connected to a load, a power supply for powering the load with at least a minimum supply voltage during normal operating conditions, and a source of battery voltage for powering the load during a power fail condition when the power supply is unable to power said load at the minimum supply voltage. The battery transfer circuit comprises a first circuit for applying at least the minimum supply voltage to the load during normal operating conditions and a second circuit for charging the battery to an optimal voltage greater than the minimum supply voltage and for down-regulating the optimal charge voltage to a predetermined voltage and for applying the predetermined voltage to the load during the power fail condition, wherein the predetermined voltage is less than the minimum supply voltage.

Growing community of inventors

Arnprior, Canada

Christopher Graham Lucas