Monday, January 12, 2009
Noises off
Awoke this morning to a low humming noise from the road side of the room. Being only somewhat awake, very concerned to find out what it was. Peered out of the window. Nothing. Went out onto the landing. Nothing. Nothing from FIL down below: no strange noises from television or hearing aids. Back to bedroom and hum resumed. BH eventually thought that maybe it was her radio, used the day before for the Archers. It then transpired that the radio was off at the radio but on at the wall. Turning it off at the wall turned off the hum.
Which triggered off much dozy pondering. Thinking that other chunks of electrical machinery hum, I think of the transformer which is presumably between the mains and the business part of the radio. My recollection of A level physics says that a transformer has two coils on a core. One coil is connected to the input power, the other to the output power. In this case input being the mains and output being the radio. Alternating current being necessary to make the input drive the output, with the ratio of the two voltages being equal to either the ratio of the number of turns on the two coils or its reciprocal. First guess, more turns on the coil makes for more volts, that is to say ratio not reciprocal. Second guess, that the radio power switch was on the output power coil. So there is still, on the face of it, an open circuit on the input power coil. So the electrons whizz around, which, in the absence of an open circuit on the output power coil, results in a balancing current being induced on the input power coil, effectively turning it off. But all the whizzing around makes a hum, but a hum too quiet to be heard if the radio is actually radioing something. Next time I have access to a suitable textbook I shall check.
Frost all melted now, but before it did, a walk around Epsom Common, still frost laden in the middle of the afternoon. Intrigued to see the leaves of the holly bushes fringed with frost bristles - little clusters of ice daggers growing out of the edge of the leaf, rather like little clusters of very small pine needles. And in some cases the little clusters had elaborated into something like a small spider's web spanning the leaf. So all very jolly and frosty until we came upon one of the various patches of the common where the trusties have been busy. That is to say they have been hiring contractors to chop chunks of it down to return it to some mythic past. Mood drops.
Which triggers off more pondering. What would I have to do to stop the trusties spoiling the common for me? I have sent off a survey form to the people who seem to have the management of the common. But this, as one would expect with a survey form, has vanished into the ether. Now I imagine that there is some voluntary committee somewhere which meets once a month to govern the common. A collection of a dozen worthy types, retired, middle class types like myself, but who happen to have a bit of spare time and nostalgia for committee work. Maybe a few retired union chaps; they seem to be keen on committees too. Maybe under the supervision of some worthy, enthusiastic young person (probably male) from the council. A fully paid up member of the 'Time Watch' fan club. The catch is that committees have to do something, that is what committees are for; they can't just leave the common alone. And they have all bought into this mythic past business. Let's make the common like it was in the middle of the 19th century. So I spend some time and bother and get myself co-opted to this committee. I'm very much the new boy so I have to keep fairly quiet for the first few meetings. This means sitting through hours of drivel about charcoal burning and sustainable woodland business. Not to mention the hobby horses of the various bores who are the bane of such committees. Get more and more grumpy. Eventually pop off. Get consigned to the bore bin by the rest of the committee, having achieved nothing. Shot my bolt. All in all I don't think it is going to work, so I sha'n't bother.
Yesterday to Nonsuch Park where another committee no doubt agonises monthly about what to do with the big house. Again, I have my pet solution (knock it down), but I don't have the patience and other skills needed to prevail on committee. Hopefully whatever they eventually come up with - and this may take a good while - will not be too ugly or intrusive.
Which triggered off much dozy pondering. Thinking that other chunks of electrical machinery hum, I think of the transformer which is presumably between the mains and the business part of the radio. My recollection of A level physics says that a transformer has two coils on a core. One coil is connected to the input power, the other to the output power. In this case input being the mains and output being the radio. Alternating current being necessary to make the input drive the output, with the ratio of the two voltages being equal to either the ratio of the number of turns on the two coils or its reciprocal. First guess, more turns on the coil makes for more volts, that is to say ratio not reciprocal. Second guess, that the radio power switch was on the output power coil. So there is still, on the face of it, an open circuit on the input power coil. So the electrons whizz around, which, in the absence of an open circuit on the output power coil, results in a balancing current being induced on the input power coil, effectively turning it off. But all the whizzing around makes a hum, but a hum too quiet to be heard if the radio is actually radioing something. Next time I have access to a suitable textbook I shall check.
Frost all melted now, but before it did, a walk around Epsom Common, still frost laden in the middle of the afternoon. Intrigued to see the leaves of the holly bushes fringed with frost bristles - little clusters of ice daggers growing out of the edge of the leaf, rather like little clusters of very small pine needles. And in some cases the little clusters had elaborated into something like a small spider's web spanning the leaf. So all very jolly and frosty until we came upon one of the various patches of the common where the trusties have been busy. That is to say they have been hiring contractors to chop chunks of it down to return it to some mythic past. Mood drops.
Which triggers off more pondering. What would I have to do to stop the trusties spoiling the common for me? I have sent off a survey form to the people who seem to have the management of the common. But this, as one would expect with a survey form, has vanished into the ether. Now I imagine that there is some voluntary committee somewhere which meets once a month to govern the common. A collection of a dozen worthy types, retired, middle class types like myself, but who happen to have a bit of spare time and nostalgia for committee work. Maybe a few retired union chaps; they seem to be keen on committees too. Maybe under the supervision of some worthy, enthusiastic young person (probably male) from the council. A fully paid up member of the 'Time Watch' fan club. The catch is that committees have to do something, that is what committees are for; they can't just leave the common alone. And they have all bought into this mythic past business. Let's make the common like it was in the middle of the 19th century. So I spend some time and bother and get myself co-opted to this committee. I'm very much the new boy so I have to keep fairly quiet for the first few meetings. This means sitting through hours of drivel about charcoal burning and sustainable woodland business. Not to mention the hobby horses of the various bores who are the bane of such committees. Get more and more grumpy. Eventually pop off. Get consigned to the bore bin by the rest of the committee, having achieved nothing. Shot my bolt. All in all I don't think it is going to work, so I sha'n't bother.
Yesterday to Nonsuch Park where another committee no doubt agonises monthly about what to do with the big house. Again, I have my pet solution (knock it down), but I don't have the patience and other skills needed to prevail on committee. Hopefully whatever they eventually come up with - and this may take a good while - will not be too ugly or intrusive.
# posted by Jim @ 12:59 AM 
