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NIK

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  1. Hi, Farnell also do a double sided sheet: https://uk.farnell.com/vector-electronics/12x12c2/pc-board-epoxy-glass-composite/dp/2850749?st=prototyping+board# Regards Nick
  2. Hi, You could also try RS, Farnell and CPC (postal charges may be a bit high at the moment). I think 1.6mm is a standard thickness. Regards Nick
  3. Hi, Re how to bridge baseboard joints: I don't know the force involved in pulling the chain along or the dimensions of the chain links but might magnets be inserted into the middle of a chain link so the link can be separated?. A 6mm diameter 4mm long N52 Neo magnet has a pull of 1.37Kg. Would have to arrange the chain guides so two magnetic pair links aligned at a baseboard. I think the system allows more than one motor to drive the same chain providing they all run at the same speed so at least one motor per baseboard may help.
  4. Hi, I'm guessing sound decoder MCUs when playing multiple sounds at the same time have to take data from different parts of an EEPROM, multiply them by the volume for each sound source add them together and multiply them by the master volume . So there may not be time to decompress the data. Then again they may have encrypted the sound files for commercial reasons but the decrypt may be done by MCU internal peripheral hardware and not have too much of a performance hit. I've never put a logic analyser on a sound chip (I assume most if not all use a serial EEPROM for the sound data)
  5. Hi, The sound chip may use a fixed rate of sending digital data to be converted to analogue. If so then the sound can't be compressed to fit. Also MP3 uses a compression algorithm that hides much the missing information from the listener as possible. It is unlikely that loco sound chips do this. Regards Nick
  6. Hi, An interesting link but judging by their inductance they are not coreless. Also the motors they have in their catalogue now are mainly too large for HO. Regards Nick
  7. Hi, I've had a good look at the photo on the Rails website and that one looks like it has metal wheels. Regards Nick
  8. Hi, I thought from NCBs post that DC controllers are being built now that don't work with coreless motors. I assume they don't have a warning on the front of them about not using them with coreless motors. Regards Nick
  9. Hi, That's a shame. It seems odd that RTR manufacturers are putting coreless motors into new designs when there appear to be suppliers of DC controllers that do not work with coreless motors and presumably don't have a warning on the front of the controller. Regards Nick
  10. Hi, There is a third reason why coreless motors don't like low repetition rate PWM. Their inductance is lower than iron cored motors leading to high rates of current rise, more energy deposited in the windings and more time at max current. By using a high repetition rate the windings spend less time at max current. Regards Nick
  11. Hi, I understand most PWM/feedback controllers designed since about 1980 use high frequency (see other topics on this on RMWeb). Coreless motors were very expensive when they became more common in kit and scratch built steam locos in the 1970's so I guess there was pressure on DC controller manufacturers to produce PWM controllers that could not burn out coreless motors due to the wrong frequency. I don't think its easy to check if a DC PWM controller is high frequency or not. I've just checked if the Bachmann Class 117 DMU uses coreless motors b
  12. Hi, DC feedback controllers are fine for coreless motors providing they use a high enough repetition rate (high frequency). Regards Nick
  13. Hi, I don't know of any controllers that limit the current in order to work with coreless motors. Peak current can be limited with coreless motors by using PWM with a high enough repetition rate to counteract the lower inductance of coreless motors. Coreless motors tend to be more efficient than iron cored motors so any lack of torque may be due to selection of a lower torque motor. In recent years most controllers have enough current to cope with most locos including some mainline OO locos by Heljan with current draw up to about 1 amps. Regards Ni
  14. Hi, If adhesion is near the limit then just a small reduction in friction between wheels and rail can result in slipping. Regards Nick
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