|
|
 |
 |
|
|
|
 |
|
MITTENTITEL |
|
Modul ?
|
|
Is this poor man's D132, or something newer, grander, better or just different ? Sorry but it is in fact a slimmed down version of the D132. Not that being D132 is bad
news, but being slimmed down D132 is disappointing. Dataprotocol If you have already read the PAGES ABOUT THE D132 PROTOCOL you already know the essentials. If you haven't read the pages, do so now. The protocol is identical in the physical as well as the semantic layer. Officially D143 supports only 3 cars, but the redbox sends all necessary commands for 6 cars and ghost- and pacecar use. When you use the cars with a D132 blackbox, the can be programmed also as cars 4 to 6, but they can not be used as ghost- or pacecar. Redbox The Redbox is built around an Atmel Mega 8. There are no real design surprises. The use of two small parallel fets instead of one bigger is the only pecularity. The little fets only have a code instead of a type printed onand that code is different from manufacturer to manufacturer. It looks like theses fets are rated with 0.9 A at 70°C each. That's not much even when two are used in parallel. There are other fets with the same package that are rated up to 3.4A. So they might be rated higher. The output driver stage has a lower than average resistance of 0.72Ω. In contrast to the usual design the power stage does not form half a H-Bridge. In this case only the supply voltage is switched by the fets and the negative potential is set by a 1 kΩ resistor. On the caseings left side there is a module connector. It's the same type as the D132 hand controller connectors. But only the signals needed for the hand controller extension and the wireless towers are connected and have identical circuitry as in the D132 blackbox. I assume carrera thought about extending the numbers of cars to 6 by the extension box or wireless controllers, but dropped the option for marketing reasons in the last moment. Hand controller The internals are identical to those of the D132 controllers, they just have a different connector (but that's external anyway :)). I was surprised that the controller didn't feel as small as it looks. Lane changer In contrast to the D132 lane changer the D143 does not have any mechanical reset mechanism. Passes a car over the IR sensor, the lane changer will set always it's direction. And the lane changers tongue will stay in that direction until the next car comes along. The signal received by the IR sensor determines which car is passing but which direction the lane changer should be set to is determined by the data strem from the track. Pitilly the D143 lane changers will have ghost- and pacecars change lanes all the time. Cars The car decoder is based on a Tiny25, just like my ProX decoder. But in contrast to that, Carrera has left only the essentials on the decoder. The IR led is driven directly by the processor, the brake fet was left off, the switching light were left off, brake light wer left off. The power stage fets seem to be rated with 0,9 A. The IR led send the cars id all the time. The signal consists of a high phase of nominally 64 µs and a low phase of 64 ¨¨. Thats a frequency of 15.625 kHz with an duty cycle of 1 to 1. Car 2 sends with 7.812 kHz and a duty cycle of 1 to 3. Car 3 sends with 5.208 kHz and a duty cycle of 1 to 5 and so on. The cars PWM runs with 30.8 kHz. Please note that even on full speed the fet isn't switched on for 5.8 µs of the 32.4 µs of one period. This means the cars reach a maximum of 82% of their theoretically possible maximum speed. The cars can be programmed for ids 1 to 6 (0-5 internally). The cars can neither be programmed as hhostcar nor as pacecar. Programmingmodes as known from the D132 are not supported.. D132 cars or decoders on a D143 track While operating in "drive mode", the redbox sends all the datapakets the D132 sends. So all features based on "clicks" can be used. That would be things, light on/off, id setting, ghostcar mode. The position of the ir led is different between D132 and D143 so it might happen that the lane changers work eratically. You can prevent this by placeing the led accordingly. When you use D132 cars with a D143 redbox, you might destroy your redbox because of the higher current drawn by the bigger cars. When using D132 decoders with D143 cars the motors might get hotter and the cars handling might change due to different PWM speeds. D143 cars or decoders on a D132 track The cars can be used as any other user controlled car. The cars cannot be used as ghost- or pace car. Programming of maximum speed, fuel and brake level are not possible. Switching lights on or off is not possible. There is no "electrical brake". The position of the ir led is different between D132 and D143 so it might happen that the lane changers work eratically. You can prevent this by placeing the led accordingly. When using D143 decoders in D132 cars the decoder might be destroyed due to the higher current draw of the D132 motors. When using D143 decoders with D132 cars the motors might get hotter and the cars handling might change due to different PWM speeds. Upgradeing Carrera Go cars BWhile testing a dual conversion with D143 it was obvious that Go cars do not work well with any of Carreras car decoders. They will handle like analog cars used with a hand controller of too low a resistance. All simple changes like removeing inductivities didn't show any positive results. The only solution was switching the motor to one out of a D143 car. The D143 motor not only works well with the D143 decoder, but also with the D132 decoder. This is the most probable reason why there are no upgrade kits for GO cars. Besides marketing and conspiracy reasons of course. Simple conversions The most obvious is replaceing the redbox with a D132 black box. It's simple to do not much to talk about. When you do this you can also convert a D132 lap counter by modyfing a GO track to hold the IR sensors of the lap counter. |
