Power supply with ecological stand by mode

摘要

The switched mode power supply according to the invention comprises a circuit 30 whose function is to reduce in an ecological stand by mode voltage output at secondary 40 of a transformer 2 of the power supply, at a minimum necessary to supply a microprocessor of an electronic appliance in which the supply is included. In a preferred embodiment circuit 30 is included in a feedback loop 15 from a secondary output of the transformer 2, to polarising means 17, 29 of a switching transistor 14. The effect of circuit 30 is then to reduce time ON of said transistor 14, leading to less output energy at the secondary of transformer 2. <IMAGE>