Has any-one used one of these in anger (ie: sneaking on next doors' cat or catching an intruder) I'm amazed how cheap they are, have just bought A Victure HC200 for a try-out, most impressive for the price. Simple to set up, the only thing I want to do is use a mains input instead of batts, there is no indication of the polarity of the input socket, can I safely assume the middle pin is Positive?