| 摘要 |
PCT No. PCT/GB94/00296 Sec. 371 Date Oct. 20, 1995 Sec. 102(e) Date Oct. 20, 1995 PCT Filed Feb. 14, 1994 PCT Pub. No. WO94/18747 PCT Pub. Date Aug. 18, 1994The converter is a switch mode converter in which a primary transformer winding (12) is switched by a power switch (Q5). The transformer secondary is wound with a power output winding (14) and a reference winding (29). The power switch (Q5) is operated by IC (24) connected as a ring-of-three oscillator. Regulation is achieved by two feedback means. First, the voltage on the reference winding (29) is peak rectified and fed back (30) to control the oscillator (24). Secondly, a signal which is a function of the on-time of the power switch (Q5) modifies the operation of a reference voltage source (Q1, Q2). The converter is particularly adapted to operate over a wide range of input voltages (typically 24 V-60 V) and over a wide range of low power (typically 24 mW-850 mW).
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