Steve wrote ... > >> > Why do you think in some areas as soon as you take the trolley > out of > >> > a certain area like the carpark the wheels lock up? > >> Does his actually happen? I've never tested it but can't think how > it > >> could be implemented cheaply so assumed it was just made up to stop > >> people trying. > > > > What, like the mythical TV detector vans?
Oh no! Not that one again!!! :-) > > I'm not sure they were a myth but presumably the disappearance of > CRT-based televisions does make the technology they used obsolete. They weren't entirely mythical but they probably couldn't do all that was claimed for them - however, they were hardly *covert* surveillance cover (as somebody suggested)! More a blatant gimmick really. As has been well discussed, the truth is that the TV licensing people rely, and have done for years, on assuming that every address has at least one TV unless proven otherwise. But yep, whatever technology they might (or might not) have had to detect the emissions from CRT television sets, flat screen LCD sets are gonna be well nigh impossible to detect (plasma screens OTOH would potentially be detectable) The trolley lock device, or at least the type of which I know, is indeed an inductive loop which releases a brake on one or more of the trolley wheels. The brake can only be released with the right key. AFAIK, there are no 'gizmos' involved in releasing the brake, it's an electro-magnetic release of a sprung loaded brake which is then reset mechanically. 'the gizmo is not working' probably translated as 'we've lost the key but don't want to admit it'. Same as where I work :- 'the coffee machine is faulty' can mean 'the coffee machine is faulty' or it can mean (but not on my watch!) 'we forgot to order more coffee beans and we've run out' or 'I can't be bothered to make coffees right now' or 'I've just cleaned the bloody machine ready for the shift change and I'm not mucking it up with five minutes to knocking off time' etc. etc. etc! On the return to duty of trolleys recovered from a canal, river etc., it was indeed the case in years gone by that the supermarkets didn't want them back because it was not economic to refurbish and clean them to put them back into service. That didn't last and more recently some supermarkets have even been willing to pay a bounty for recovered trolleys - last I heard, which is a good decade ago, if not longer, was that the cost of refurbishing was about half that of replacement. Bru
