| 摘要 |
A switched mode power supply circuit of the forward converter type which has a plurality of output circuits is provided with a control circuit 28, for stabilising an electrical quantity, such as voltage, at the output terminals 32, 33 of at least one of the output circuits. The relevant secondary winding 2 of the converter transformer feeds a flywheel circuit 14, 20 via a rectifier 13 and a saturable choke 27 which is provided with a control winding 28. During each "off" period of the converter the induced voltage across the control winding is clamped using feedback 31 at a value proportional to the output quantity to be stabilised thereby controlling the demagnetization of the core material of the choke which occurs during each "off" period, and hence the magnetization which it has when the next "on" period starts. In an alternative arrangement a steady current determined by the value of the quantity to be stabilised is passed through the saturable choke control winding. <IMAGE> |
