Hi Astro
Great feedback.
QUOTE (astro @ 11 Jan 2005, 17:11)Fabulous work as always. At first the DOC document did not come up, but it did today.Thank you.
QUOTE Suggestions and comments detailed. Obviously this is a list of things that I feel deserve comment or could imho be done differently, it is not intended to come over negatively.Don't worry ... I won't take it personally.
The reason I put the specification up here, is because I want the weaknesses in the system design to be identified before I get too far in the design process.
QUOTE Firstly regarding the guide method of ID -
This would work elegently for me on the old scalextric blue guide system - simply snap out the guide number 7 and click in the guide for car ID 12 when needed. But changing the ID of cars with other guides can be fiddly. The new scalex type is screwed in from inside the car, others have the wires soldered to the braids or use those bullet things - I hate changing those guides cos the braids never go back the same!You certainly have a point here ... perhaps making slots in the guide blade is more cumbersome than mounting the LED sensor in the bottom of the chassis?.
I'll try if I can think of a better idea ... perhaps if we could design a system where you can mount small photo blockers in the guide holes or slots, and set the address without the use of tools.
That way you always have to make 4 holes or slots, and block the ones you don't use. I think the major problem would be to make a design that won't fall off in the slot, but who knows ... it might be possible.
QUOTE also - the variety of guide types means that the system presumably would not come with a set of guides, but people would have to saw their own. I am just trying to envisage how this would work in clubs where the cars need to be recoded etc.Yes, I agree ... we need someting that's simple to configure.
IMO the ability to place a lane change anywhere, regardless if the cars are sliding, is rather nice though.
QUOTE Sector Timing -
It is my understanding that you are planning to use the LCs to divide the track into sectors. Since at the moment people are generally thinking of evenly spacing LCs, this makes a lot of sense. However, maybe a sector track should be a seperate thing to an LC? It would make track/sector design more flexible (eg you might want to set up a couple of sector dividers so you can time the velocity along the long straight of your track)Yes, I thought we could use the sensors that have to be there for lane change, for lap and sector timing as well.
There should not be any problems in placing lane change drivers anywhere on the track. If you only need the timing functions, you can leave the solenoid outputs unconnected. Also there should be no practical limit to the number of lane changes you can put on the track
We might even be able to do something clever with a lane change sensor at each pit garage in the pit lane?.
QUOTE High Voltage Low current -
I understand what you are saying and the advantages of this. Thers a few things I don't quite follow:
Say a given car in analogue goes top speed at 12 volts DC, drawing 2 amps. power used = 24 watts, and it goes at a certain speed.Exactly.
QUOTE Now with the high voltage system, we are sending the car 24 volts, but only allowing it 1 amp (again 24 watts) Is the chip inside the car supplying the motor with 12 volts 2amps, or 24 volts 1 amp?This is a bit tricky, but I'll try to explain it. Please bear with me if this doesn't come across in a logical way.
The car will deliver 24V 2A 50% of the time. If the signal change quick enough, the motor will see this as 12V 2A 100% of the time.
This is because a motor forms an inductive load. If you apply a voltage to an inductive load, the voltage will appear without delay, but the current will rise slowly according to the time constant of the inductance. Likewise the current will disappear slowly when you remove the voltage (the inductor will continue to deliver current while the magnetic field in the inductor collapses).
This is opposite a capacitive load, where the current appears immediately and the voltage rises slowly.
The power supply will deliver 24V all the time, but it will deliver 2A 50% of the time, and 0A the other 50% of the time. In average this will draw 1A from the 24V power supply.
QUOTE If the chip is supplying 24 volts but limiting the current, then the car motor will be running in a current starved situation. Even though it is recieving the same power, will it behave the same? and what about at 22 volts? Has this method of motor control with current starvation been tried in the analogue (or digital) environment before it is implimented?If the voltage drops to 22V, the car regulator must increase the duty cycle from 50% to 55%.
QUOTE I just know that home racers get frustrated with power when there is not enough current, and in analogue the best driving is unlimited amps, adjust voltage for top speed..You are right. I think that adressing the power supply and power sharing issues, wil be one of the most important features with the new CarDCC system.
QUOTE Hand controller connector
jacks or mini jacks - although cheap and small, are not the most reliable of connectors, and the cheaper sockets sustain wear and corrosion quite quickly. Something with seperate pins (XLR/cannon connectors are excellent but pricy and bulky - telephone connectors as used by SCX and Carrera are probably the best except they are fiddly to wire) would in my opinion provide better longterm reliabilityIt's certainly possible to use other connectors ... I'll check if it's possible to make a dual mounting option, so that you can chose if you want minijacks or RJ telephone connectors.
Those vere very usefull inputs sofar.