Sunday, 8 December 2019

Tunbridge Wells Constituency General Elections 1885-2019

I don't know if Tunbridge Wells has always had a Conservative or a Unionist MP but it has been at least since 1885, except for 1906.  Until 1910 the Liberal Party came a close second or won in 1906 and during the 1950s the Labour Party also came close to winning the seat.  From the 1980s until 2010 Lib-Dems had been second but they have moved to 3rd or 4th place whilst the Labour Party had been gaining ground again since the end of the 1980s.

The 2019 General Election timing was chosen by the Conservative prime minister for best advantage for that party, with help of the Lib-Dem leader and despite having fixed term parliaments.  Generally, electors rejecting coalition of any sort despite, Michael Heseltine, John Major, Tony Blair and others recommending something like that.   Locally the Lib-Dem's gained by heavy leafleting (the number of trees lost did not count against them) despite the usual trend but Labour fielded a candidate with an out of the constituency address.

There was a short time when Conservatives did not run Tunbridge Wells Borough Council and Kent County Council in the 1990s.  You can also see the inevitable downward trend in Labour voting in General Elections when Labour was in power this effect is not apparent in Conservative voting in general elections.  Conservatives vote for other party's some making a point of voting Labour in local elections when they don't like what their party is doing nationally.  Also in Local Elections from 1990 Labour followed an upward trend but in General elections the trend fitted the pattern I suggested and the trend was downward whilst Labour was in government.

Observations from looking at the data and discussion;

Before WW1 - General Elections probably happened when members chose to step aside.  So there was a more gradual change - the system seemed fairer but that the franchise was only for men with property. 

We could do with both the franchise widened plus that voters all getting to vote without problems.  We could do with the media to behave better or be shut down completely.  I am sure people feel they got it wrong because they listen to the media so don't vote next time.  

The 2019 election;

Conservatives have been winning elections for the past 30 years by promising to leave the EU to a minority but not delivering that promise.  This has been a good strategy for them because their is no other party likely to carry out leave.

Even if we never have another Labour government.  Momentum, Jeremy Corbyn and his team have inspired a considerable number of people to get into politics for the good.   People of an alternative viewpoints voted who have never voted in 40 years.   The Labour opposition have high success rate in opposing successfully many of the a very nasty party's measures.   That nasty party could not change but instead beat its own MPs in to line.  Perhaps even Mrs May wanted change but there were Conservatives who said the last 40 years were a mistake - in this election campaign.  That has been said across party's for a few decades.

Lib-Dem leader gave this election to the Conservatives by letting them chose when it wanted an election.  Of cause the Conservative government chose before Brexit so that Leave campaign did much of the work.  The outcome though is that all party's followed Labour's look after the little people promises in there manifesto's.  Still I am not expecting Boris Johnson to be a Socialist in Wolves clothing?

Mistake of the environmental campaign in the 1990s may now be overcome;

The Campaign for Nuclear Disarmament were very effective taking care not to divide amongst themselves on strategy.  The old guard from the 1960s guided new member's well from 1979 when Cruise Missiles and Theatre nuclear war was being deployed for in the UK and Europe.  In the 1990's the environmental groups divided and criticise strategy's.  They employed advocates rather than environmentalists and activists.  The environment, social rights and other things than self interest have started to inspire more young adults again.  

Presentation prepared for; Extinction Rebellion London University's Strand the Strand event in September 2019 that was broken up by the police. Based professor Keith Barnham's book, The Burning Answer;

The young people must not give up - they share the same enthusiasm that people now over 85  had in 1945.  The 2019 Labour Manifesto was more easily achievable and exciting however they voted.  The manifesto did not have the an anti-nuclear war policy that the 1980s Labour manifestos had despite that policy having been supported now by the public for the past 20 years.


1885-1910 Tunbridge constituency;

1916 No general election due to World War 1.  Term reduced to 5 years.

1918-1970 Tonbridge Constituency.  Franchise widened to Women and people without property.

1974-2018 (present) Tunbridge Wells Constituency

BBC 2019 election results.

Turn out percentage for 1956 found in a government document found on the web.  The figure looks correct for the given the poll.

Post General Election Momentum and The Labour Party - this video might be deleted?

Pre-election warning - I am in any-case very surprised out how well Labour and Momentum did inspiring people mostly younger voters but also voters over age 85 who remember how it was before the NHS.   Those now very old voters liked the manifesto seeing simply a 1945 Labour manifesto.

Thursday, 18 July 2019

Bicycle Hub Dynamo maintanance - Project plan notes

 Changed; 03/05/2020 to 06-05-2020
To discuss the electrical issue with some textbook motor and generator theory.  I do not have a dynamo to experiment with yet.  All so-called dynamos are really AC generators they have no brushes and they are identical to many electro-mechanical mains voltage timers motors such as used to be used in central heating timers.  Some such as a hybrid stepper motor which produces alternating current in a number of phases and at low speed.  This type of motor or generator is called a Permanent magnet synchronous motor or generator.

At the bottom of the page, there is a bicycle dynamo light and battery manager with a speedometer design idea.  It interfaces by USB cable.

Graph - Current can be drawn up to the same limit irrespectively of the generator speed and then the 
voltage will drop sharply.
Small graph - With no load, the output voltage increases linearly proportionally to the speed of rotation.

Risk of the magnet demagnetising; 
The magnet will demagnetise if separated from the armature so if you remove the armature you need to replace it with a keeper such as another armature.  A magnet keeper is a piece of soft iron that conducts magnetism very efficiently.  Mu-metal that transformers,  motors, generators and the screen on old colour TV CRT use is ideal.  The metal should not be bent or hammered because this hardens the metal and reduces the metal's desired qualities so you should minimise the amount of work you do on the metal.

A dynamo hub bearings can be serviced without separating the magnetic parts the magnet and the winding so a keeper may not be required.  Although the amount of cleaning will be limited either way.

 Colour TV, CRT magnetic field screen made of mu-metal.

The Plan;
To cut a piece of mu-metal and carefully bend it into a radius.  In more detail like a C shape but more like a G shape with a small gap so that the metal can be shrunk to fit it then expand into the cavity where the armature was.  The G shape so that there is a tale that can be pulled on to unstick and remove the keeper.

The estimate of the dimensions;
Apparently, there are many different size hub dynamos.
  • BSA and others - many sizes I don't know. 
  • Sturmey-Archer
    • GH12 (1936-38),  111mm outside diameter. 12V
*** It turns out the estimate from photos is wrong and a GH6 or GH8 hub distances between the bolts is 75mm. So the keeper will need to be about 70mm diameter. ***

The estimate of magnet inside diameter 63mm was wrong for the GH6 or GH8 the correct figure is 75mm.  That figure to scale  the figure for the GH12 to 96.5mm = 81mm * 75mm / 63mm. Therefore a length of metal; 302mm.
    • GH8 (1938-41),  90mm OD, 8V
    • GH6, 90mm OD and are also the same as the AG and FG gear hub dynamos.  6V.
      • Magnet bolts dia; 75mm.
      • The length of mu-metal required is the circumference;  235mm = pi.D.

The width of the metal looking at pictures the hub dynamo looks as if is less than half the width of the hub.  That is less than <25mm = 50mm / 2.

I understand that all post-world war two dyno hubs and gear dyno hubs are the same and parts interchangeable. The external appearance changed from time-to-time though.

Picture - Making the keeper by finding a glass jar of about the right 
diameter, wrapping it in a rage then bending the mu-metal around the jar.

Dynamo magnet keeper's;
I have some mu-metal and have cut a piece 30mm x 260mm x 0.5mm - it looks messy because I used kitchen scissors and it would be better cut with a guillotine to make a magnet keeper for a GH12 hub-dynamo. My plan is to carefully bend into a C shape radius. Actually more like a G so that there is a tail facing in to pull it out with.
I will cut more pieces for other old dynamo types but I need to know the internal circumference (diameter x pi) so if you tell me the diameters. Otherwise, if you have a way of cutting soft steel I shall bring the whole sheet to cut.  Then I can return home with what is left.

Testing the dynamo;

 1. With the bike wheel off the ground so that it can be spun freely;
  • GH 12 - I believe the circuit is two 6V filament lamps in series rated at 150 mA.  Short one lamp to see if the other lamp illuminates then short the other lamp this will determine if there is a simple lamp failure.
  • GH 8  - I believe the circuit is two 4V filament lamps in series rated at 250 mA. If the circuit is the same as the GH 12 then the test is the same.
  • GH 6 - The circuit is two 6V filament lamps in parallel rated at 100 mA and 200 mA. If one lamp fails then the other lamp will fail so, therefore, turn the wheel slowly at first to see if there is some light from one or both lamps.
2. With the wheel removed from the bike and the bearings set properly;
  • Turn the shaft and notice the dynamo detent force - which feels springy sort of lumpy and is very light.  It does not matter which direction the wheel is rotated in the output is alternating current in any case.
  • Short the dynamo output with a wire.
  • Turn the shaft and notice the dynamo stronger magnet resistance force - which feels springy lumpy but is significant.
If the force was different as described the magnet is magnetised and the dynamo is good or the magnet is could be week.

If there was no difference then;
  • If the force is week then the winding may be open circuit or the magnet is demagnetised.
  • If the force is strong then the winding may be short circuit but the magnet is good. 
If there is doubt about the lamp and the dynamo circuits test the lamp circuit with a battery instead of the dynamo.  Of cause, you can test with a multimeter rather than traditional methods but a multimeter in its time like an AVO might cost more than a new bike in the 1930s.  The current from a resistance meter if connected to the dynamo will cause a small high voltage spark when you disconnect it (called back-EMF).
The second tool rematerialising the magnet;
This is the same process that happens with a computer hard disk.  A very high pulse of magnetism is applied to the hard iron material to magnetise it.  Such a pulse will also switch a magnets polarity north and south poles. This is done with the dynamo fully maintained and assembled then briefly connecting a high current from a voltage power source to the armature.  The risk is the high voltage could cause the armature winding if it is weak to break down and fail but in that case, the armature was probably going to fail anyway.

AL-0030-01A C1 is trickle charged from a high voltage.  When S1 is closed a pulse of increasing
current is connected to the dynamo winding represented by L1, 1H.  D1 prevents the circuit from
 creating a high voltage, ringing (oscillating), arcing and demagnetising the briefly magnetised 
magnet.  The voltage and component values are to be determined.  The Ground connection 
shown is not earth but is a reference point for simulation.

Allow the small detent force (the magnetism) to pull the armature to align the poles ready for the pulse of current to re-magnetise.  You can test the magnetism by turning the armature to feel the lumpy pull of the magnets to the armature sections.  This detent force is much bigger if you short circuit the armature and doing that will confirm that the winding has continuity and is not short circuit.
    In due cause, I will make a re-magnetising circuit using a high voltage trickle charge circuit with a capacitor and a diode and a switch.  How it works is that it produces a high current pulse - standard physics stuff but I need to experiment to find out how high the current needs to be?
    The device will of-cause deliver a dangerously high voltage. 

Simple alternative using a DC power supply and diode;

The high voltage discharge circuit above could be replaced by a DC power supply such as a car battery charger.  The charger is connected to the dynamo then in a different method, the dynamo shaft can move freely so that the magnet poles align when the pulse of magnetism is applied.

Next step is as before switched on for 1/10 second then off but 1 second would be okay.  Take care to switch off quickly so that the dynamo winding does not heat up.  Do not disconnect the dynamo whilst the power is switched on because a high voltage, called back-EMF, will be generated that will put the winding under stress unnecessarily.  See diagram below; 
AL-0030-01A The car battery charger has an internal rectifier diode so another diode is not required.
Connect up then switch on for 1/10th second to 1 second then turn off.  The setting of the low or 
high charge switch will make little difference other than to limit the armature heating.

What happens; The armature (generator winding) of the dynamo (generator) will move and the magnet poles and armature segments will align or re-align as the current and the magnetism increases. The field magnet normally moves but this is stationary and will be magnetised.


Bicycle dynamo light and battery manager;

Microcontroller based bicycle dynamo light and battery manager with a speedometer.  Design idea and exercise with STM32 microcontroller.   With interface by USB cable for speedometer display.
  • Manage two cell NiMH battery charging using a coulomb counting method. Therefore it is best not to remove the battery's in order to maintain the battery state of charge and capacity.  Therefore use the USB port charging.
  • On PCB bootloader switch for fast programming via USB port plus software debug connector.
  • Software proposed functions;
    • Switch to turn on Dynamo power to the USB.
    • Switch to turn the lights on. 
    • Red/Yellow/Green - battery charge status LED. 
    • Blue - USB connected status LED.
  • Manage maximum power transfer from a bicycle dynamo or alternatively with component changes a two, three or four-phase stepper motor.

Link to CADSTAR 18 and STMCube files Draft more to follow.

List of files;
There is a spreadsheet list of files *.xls

AL-xxxx-xx -- minimum LED lighting,  does not require PCB and can be made using Veroboard.  (to follow)

--- Basic bicycle dynamo battery and lights manager  ---
AL-0002-01C Circuit and PCB's - draft. The design should fit in under 100 x 100mm.
AL-0033-01C.ioc Micro-controller selector and configuration project file draft (out of date).

 ---- The PFC front end is not a good solution but shows functions required a software-driven PFC would be better ---
PCB size 150x100mm 4 layer components on one side. - to follow
  •  AL-0002-02C -- with PFC front end for wider voltage range and more efficient power transfer. This shows in function block what can be done in software more efficiently, fewer compromises and cheaply. 
  • AL-0033-02C.ioc -- Micro-controller selector and configuration project file draft. software to be finalised. STM CubeM.
  • AL-0034-01A - dynamo battery lights manager Synchronous rectifier controller.wxsch  SiMetrix 8.3 simulation.
--- Software driven PFC front end TO FOLLOW  ---  
AL-0002-3A -- with software driven PFC front end for wider voltage range and more efficient power transfer.  (to follow)

Improved LED efficiency can be achieved by using a boost switch-mode current driver.  Some of these can be driven from a pulse-width modulated power supply for dimming power saving.  For example;  Diodes Ltd - Low voltage led drivers 


Pandemic cycling and bicycle selection going-forward

Raleigh Lenton sports bicycle  + General maintenance advice, technical and history.