电路窃取从并行端口，功率为 8mA 在 5V 提供效率高达 94%。Maxim > App Notes > AMPLIFIER AND COMPARATOR CIRCUITS POWER-SUPPLY CIRCUITS Keywords: power conversion, parallel port, stepup switching converter, Schottky diodes Mar 14, 2005 APPLICATION NOTE 3468 High-Efficiency Step-Up Converter Robs Parallel Port Abstract: Circuit including a step-up switching converter steals power from a parallel port, providing 5V at 8mA with efficiency as high as 94%. The circuit of Figure 1 steals energy from a parallel port or from any limited-energy source. Such power- conversion applications usually require very high efficiency for making use of the energy available. A parallel- data port, for instance, provides as much as 2.6mA per data line at 2.4V. When the eight data lines are software- configured to FFHEX (all high), that conditi……