PSU section and batteries

Discuss mods, hacks, tweaks, etc.
  • No, a TR909 does not run on batteries, the batteries hold all patterns in memory when powered off...
  • Haha. That makes more sense.. ;)
    And explain why the only battery mentioned in the schematic was one of those small cell batteries typically used for such things :lol:
    I just saw the battery cover and thought it could run on batteries just like the 101, 202 and 303 (never been close to a real 909, thus the question)
  • Technically it's possible to run almost everything from batteries, the real questions is how much batteries you need and how long they will last before device becomes unoperational. Ideal case for powering nava is two ideal batteries that output constantly 15v until the end of its charge, connected together to provide -15v GND +15v, it's even better than 7815/7915 regulators! But the realword batteries will drop potential while they give power, so they will drop voltage to unacceptable levels sooner than they will deplete most of their charge. That issue can be overcome by impulse step-up converters, so you could use most of the battery charge, but it would be noisy, so here you go again - you need regulators to receive clear output voltage and loose some efficiency on step-up and regulators... Another problem is that nava power requirements can be like an average laptop/netbook, around 30w. So anyway, for the device of this class/size its a bad idea - you have to use a lots of batteries to power it, or a very specific ones, and they will not last that long, even if you will use a step up converters. It would be more practically to put inside some li-ion cells and a power switching / charging circuit, so it would run for some time like an average laptop around 3..10hrs (depending on the cells count). But as a downside you've got the noticeable additional weight ...