parking meter alarm

In most large towns and cities (for that matter, in many small ones as well!), the parking meter is a very familiar sight. Installed in both likely and unlikely places in an attempt to alleviate the problem of insufficient parking spaces and at the same time, as profitable (?) sideline, to raise a little money which can then be spent on more `no-parking` signs, the parking meter seems to be becoming a status symbol for progressive communities. If one is careful parking is still relatively cheap, but if one forgets to get back to the `mechanical wonder` before it gets hungry again, one runs the risk of making a much larger donation to the city treasury. By letting you know when your time is just about up, the little unit described here can pay for itself in one go.