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DeTRacted

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  1. DeTRacted

    Trigger Wheel Mounting Vitesse

    I'm not sure whether you are still discussing RS232 cables or not - but just in case you are, when connecting two devices directly together you usually need a 'null modem' cable in which the Rx and Tx lines are crossed. The reason for that is that you need Tx on one device to talk to Rx on the other. However a plain RS232 cable is not connected like that because there was supposed to be a Modem (modulator-demodulator) in the way which provided that cross-connection. Hence the name null modem- because there is no modem in the circuit. Both types of cables and connectors look the same and its easy to get confused. Rob
  2. No John - earthing of a magnetic screen isn't necessary. What is happening is that a varying field induces currents (eddy current) in the metal and these currents act as small electro-magnets to effectively cancel out that applied field for anything within the screen. It all happens within the thickness of the metal.
  3. Aluminium can help for higher-frequency fields if it is thick enough and forms a complete Faraday shield John, but this is a low-frequency thing and here you really need a 'magnetic' material. Mu-metal is a pretty expensive option but is about the best. µ is the permeability factor and this stuff has a very high figure - hence the name. It has been used for decades in high-quality electronics and telecoms applications as your link explains but its really overkill for things like this. It's possible a bit of steel conduit tube around the body of the sensor would do the trick, or even a flat steel plate between it and the motor though that wouldn't do much for the efficiency of the cooling fan.
  4. Just a thought - its possible the interference from the fan motor may not be electrical - it could be magnetic in which case suppression capacitors and earthing won’t help. The pickup is very sensitive to rapidly moving magnetic fields and the fan motor has electro-magnets whirling around inside. Screening that may prove difficult. Ideally you would need a soft iron plate between the two, though it might be enough if the sensor body was enclosed in a steel box or tube. (ali won’t work, it has to be ferrous). Rob
  5. DeTRacted

    Electronic flasher relay...?

    To use a mix of bulb types you will certainly need an electronic flasher unit (because the old bi-metallic type needs the correct bulb current to make it work). In theory there is no need to change all the bulbs but you will need to change the hazard flasher unit too. BUT the choice of flasher unit is crucial, particularly with the two-pin variety. These need the bulbs to complete the circuit for the flasher internals and will be sensitive to the load you apply which could affect whether they flash at all or the speed at which they flash. A standard two pin electronic flasher may not be happy with a mainly LED load while an LED type may burn out if you try to drive standard trailer lights too. You might be lucky with a standard unit but only trial and error will tell. You might be able to find an LED unit which can also supply normal bulbs but it would probably be much simpler, if a bit more expensive, to change everything to LED. Make sure you connect the polarity correctly for the flasher units. If the wires have been crossed the bimetallic type won't care but an electronic one will not work.
  6. DeTRacted

    Alternator Excitor voltage

    Is this a Lucas ACR alternator? If its the three-pin connection type the third pin is only an 'exciter' input until the engine fires up. Once the alternator is spinning the field excitation comes from an internal connection to the 'triple' rectifiers and the lamp goes out because the voltage is about the same on each side of it. If yours is still lit with the alternator running there is a fault in the alternator. Connecting the indicator pin to 12v will not help.
  7. DeTRacted

    Trigger Wheel Mounting Vitesse

    The sensor waveforms look believable John but the video of the sensor output shows occasional tall spikes which look random and are difficult to explain - was the sensor brushing the wheel sometimes or perhaps it's electrical pick-up from somewhere? Could be computer-generated noise I suppose. Either way they aren't on the cranking waveform so it shouldn't stop the unit working. The random output is very strange. If the EDIS just wasn't able to trigger on the sensor waveform you would expect a flat line. Rob
  8. DeTRacted

    Trigger Wheel Mounting Vitesse

    Yes it looks like the sensor is probably OK John. The peaks may well be ten times as large as your meter says. Rob
  9. DeTRacted

    Trigger Wheel Mounting Vitesse

    A VR (variable reluctance) sensor is basically just a coil would round a magnet. Very little to go wrong and you can can do a basic check easily by measuring for coil resistance between the connector pins. In your test you may be being fooled by your multimeter - I guess its a digital one which you have set on AC volts? The output of the sensor will be spikes which the multimeter cannot handle properly because it is calibrated for sine-waves. It is probably reading the average of the spikes which will be quite low. You really need an oscilloscope for that test. Rob The 'sort of' sinewaves shown on the TriggerWheel site are at 10000rpm where everything has smoothed out due to time-constants. At 160 rpm the waveform won't look like that at all.
  10. DeTRacted

    Trigger Wheel Mounting Vitesse

    A VR (variable reluctance) sensor is basically just a coil would round a magnet. Very little to go wrong and you can can do a basic check easily by measuring for coil resistance between the connector pins. In your test you may be being fooled by your multimeter - I guess its a digital one which you have set on AC volts? The output of the sensor will be spikes which the multimeter cannot handle properly because it is calibrated for sine-waves. It is probably reading the average of the spikes which will be quite low. You really need an oscilloscope for that test. Rob
  11. DeTRacted

    Trigger Wheel Mounting Vitesse

    Go to Maplins John - they sell in singles. https://www.maplin.co.uk/p/metal-film-06w-1k-ohm-resistor-m1k Rob
  12. DeTRacted

    Trigger Wheel Mounting Vitesse

    Grounding and shielding of circuits can seem more of a black are than a science. What it is trying to achieve is to prevent pickup on the protected (shielded) wires from external sources of electrostatic noise. A continuous wrap like copper foil does this better than braided cable, and forms a partial Faraday screen (partial because of course you cannot close the ends ). For this to work properly it is important to prevent noise currents circulating in the shield itself since these can couple noise magnetically into the wires, so the shield should be connected to earth only at one point. More than one ground will result in a ground loop a.k.a. earth loop. That is also the reason for the note about grounding everything at the same point, since in radio-frequency terms different points on the bodywork will be at different potentials.
  13. This quote from the Revington website re the 4 pot engine: Q: If I fit a plastic fan to the original fan extension or remove the fan and extension altogether, would I be risking crankshaft breakage or damage due to changing the dampening effect of the original fan/extension arrangement? A: Irrespective of whether you use a wobbly aluminium fan or a wobbly plastic fan, the effect is the same. It helps (just) to cool the engine and that is all. In our opinion the amount of damping it offers is negligible. Dampers have been in use since the 20's where necessary. If Triumph (one of the largest sports car manufacturers in the world at the time) thought is was necessary they would have fitted one. We have been building TR2-4A engines with no fan and no extension for 25 years with NO broken crank related failures. As a result we are quite happy that an engine in good shape, from standard up to all bar the highest revving competition engines should not suffer ill effect by having the fan substituted for a later TR6 plastic type or having it and the extension removed altogether. If you do remove the fan altogether we recommend using a properly designed washer and bolt arrangement to hold the pulley to the crankshaft.
  14. The other side of the argument: https://notalotofpeopleknowthat.wordpress.com/2017/08/15/claims-of-40000-deaths-from-air-pollution-debunked-by-death-statistics/
  15. I think we need to take these BBC things with a pinch of salt Darren. According to this website there are not that many measuring points across the UK: https://uk-air.defra.gov.uk/latest/currentlevels?view=site Is ther one in your village ? because if not they are just quoting the nearest site which could be miles away - so the figure would be meaningless.
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