What's a good circuit to get a stable 5V from a Tab SumoBot powered by (4) AA batteries? I'm currently using a regulator diode to drop the battery voltage from 6V to 5.3V, which is good enough to drive a HD44780 based LCD. But when the servo's kick on, this voltage is reduced from 5.3V to 4.8V. While this is within the specs of the LCD (5V +/- 10%) - I can't believe this is good for long-term use. While the Tab SumoBot is driven by an embedded BS2, Vdd is not available on this robot. The BS2 is driven by Vcc regulated to 3.9V - which isn't high enough for the LCD.