| 摘要 |
The invention is an in-line voltage transformer. The invention converts input voltage from 9 volts to the selected output voltage. The output voltage options are 12, 18 and 24 volts. Thus allowing various signal processor or effects (requiring different voltages) to be powered from the same voltage source. The invention works in conjunction with a digital 12 volt power supply. The input voltage (9V) passes through a filter comprised of two capacitors C 1 (1 muF) for low frequencies and C 2 (1 muF) for high frequencies. The current then goes into a constant frequency (1.2 MHz) current mode boost switching regulator controlled by U 1 . The VC pin on U 1 provides loop frequency compensation [comprised of C 5 (100 pF), C 7 (6800 pF) and R 4 (6.8K 1%)]. This compensation reduces the output voltage ripple. U 1 uses L 1 (high frequency 10 muH inductor) and D 1 (low drop, high frequency schottky diode) to step the voltage up. The output voltage is set via feedback resistors that are switched in and out to provide the different out put voltages. 12V is set by resistor divider path R 1 (169K %) in parallel with R 3 (191K 1%) and in series with R 5 (10K 1%). 18K is set by resistor divider path R 2 (536K 1%) in parallel with R 3 (191K 1%) and in series with R 5 (10K 1%). 24V is set by the resistor divider R 3 (191K 1%) in series with R 5 (10K 1%). The output voltage is filtered by C 3 (for low frequencies) and C 5 for (high frequencies). The chassis is a two part cylindrical housing made from ABS HB Black resin. Connecting wiring consists of an input connector which consists of a standard polarity (Tip-positive/Barrel-negative) female barrel connector. The wiring is standard coated 16 gauge.
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