26-02-2016, 08:22 PM
The regulators using the AD149 or simmilar continued well into the silicon era (im thinking of the Thorn sets) with portables that could run on vehicle starter batteries due to the probably incorrect idea that it allowed operation with lower headroom. Basically a battery of that type with much less than 12 volts at its terminals is pretty much discharged anyway, so Jeffrey has a good point about the type of pass transistor. As for using the original idea with the nicads, hmm, well its keeping things original but in that case I think that a crowbar circuit may save some tears should the worst happen, unlikely as it may be. 17watts consumption Geordie? Amazing! I don't think TV manufacturers managed to better that much for any portable of that size in the CRT era.
