Wheelie II

[manuel silva]

Hello!

I would like to build a wheelie II , is there someone who is willing to help me and give me information in order to start doing it?

Where can I get the latest information?

Are the PCB's sold by some one or we must make them ourselves?

Thanks in advance.
Manuel

[manuel silva]

Hello Thomas!

Just one more word. I knew the puting that post I was closing any help I could get from this forum.

Regards,
Manuel

[manuel silva]

Hello Thomas!

I know that no one is obliged to answer to my inquires, but, the goal of the forums is to share ideas, experiences, knowledge and help other. This is my view about the purpose of the forums, considering this I was expecting some help, even to say that I was making the wrong questions.

Another reason that influenced my behaviour is because I had already bad experiences with other German forums, and some are for support people that buy products (kits) from the owner or moderator of it, where the foreigners were forgotten.

I know the language is a problem, to understand German I have to use the google translator, but, (there is always a but) the question "Are the PCB's sold by some one or we must make them ourselves?" isn't this a direct question?

Any way I want thank you for your comments, at least, some one answer to my post.

I really would like to make a wheelie II, (not for me, because I am already 65 years old), but, to offer to my grandson.
Considering all the linguistic barriers I must give up.
It was just a dream!


Thanks any any.
regards,
Manuel

[manuel silva]

Hello all!

I would like to be politely, but, after several attempts go get some help and answers I didn't get none. I think in this forum there is some kind of people selection or separatism, may be because I am not German.

I don't think it is fair enough, considering it is a public forum. I consider it a kind of disrespect, if you do not want to share the information say it directly.

In my country we use to say every person deserves an answer even a monkey even a no.

regards,
Manuel

[thomas scherer]

Hey Manuel,
please take a deep breath and come down!
The fact, that you got no answer may be caused by you!
Your question is very very broad and totally general.
In my eyes this is the answer.
If one want to help you he does this voluntary.
You have no "right" to get answers…

You better show that you try hard to get infos yourself.
Afterwards you should be able to aks precise questions
instead of more global ones - thos will rise the chance
to get answers even in english.
The most Infos you can find here in the forum.
But it is much to read (and to understand)

This is a german forum. It is clear that it would be hard to extract the information if you cant read german at least a bit.
But this fact will never ever give you the right to expect that someone will do the work for you. And for not native english speakers the agregation of information and translation into english IS work.
Don't be surpised that the sound of your last post will not rise the chance to get help.'

[guenter]

Hello,

-i dont know if there is an moderator here
-i dont sell PCBs yet, the H-Bridges are not good enough.
-i share all my work here
-i answer Questions only sometimes like any other here

Günter

[guenter]

Hallo Forum,

im letzten Jahr habe ich ja versucht die Grenzen der H-Brücken auszuloten. Der Versuch eine Skateboardrampe hochzufahren endete mit abgerauchten Endstufen. Meiner Meinung nach dürfen Bleiakkus explodieren, Motoren durchbrennen, Steckverbinder schmoren oder Sicherungen durchbrennen. Aber eben keine H-Brücken.
Die Herausforderung ist zum Einen die Leiterbahnen breit und dick genug zu machen, zum Anderen den Widerstand der Transistoren zu verringern.
Die Anordnung der TO220 Transistoren an einem Kühlkörper setzen dem Layout jedoch enge Grenzen. Deshalb will ich jetzt auf D2PAK-7 umsteigen und zusätzlich je 2 Transistoren parallel schalten. Meinen Berechnungen zufolge müsste das Treiber-IC das können. Der Widerstand einer Schaltphase (immer 2 Transistoren) sinkt dadurch von 9mOhm (2xIRFB4110) auf 3,8mOhm (IPB019N08N3). Die Sperrspannung der neuen Infineontransistoren von 80V reicht für den 36V Einsatz locker aus.

[guenter]

Die Leiterbahnen:

im Bild grün die Zuleitung über den Stromsemsor zu den zwei oberen Brückenzweigen. Grau und braun jeweils Drain und Source zusammen zu den Motorklemmen. Zum Schluss in Blau der weg zum Minuspol der Batterie. Da die Minusleitung durch die Gatekontakte der unteren Transistoren eingeschnürt ist, habe ich 7 Bohrungen für Drahtbrücken oder ein Kupferblech vorgesehen. Somit wären die engsten Stellen auf beiden Lagen immer noch 10mm breit!

[guenter]

Die Wärme:

Man darf davon ausgehen, dass die 12Ah Bleiakkus über ein paar Sekunden 100A liefern können. Das würde an den vier durchgeschalteten Transistoren eine Verlustleistung von 19 Watt verursachen. Pro Transistor also etwa 5 Watt.
Die Wärme soll über Vias zur anderen Platinenseite abgeleitet werden. Dort sitzt ein Kühlkörper direkt auf der Platine auf.
Der Transistor hat einen Wärmewiderstand von 0,5 K/W. Laut http://www.electronics-cooling.com/2004/08/thermal-vias-a-packaging-engineers-best-friend/ Hat ein 10x10 Viafeld 1,7 K/W
Der Fischerkühlkörper ICKS50x50x50: 0,5K/W also 2K/W pro Transistor.http://www.fischerelektronik.de/web_fischer/de_DE/K%C3%BChlk%C3%B6rper/B03/Stiftk%C3%BChlk%C3%B6rper/PR/ICKS50x50x50_/index.xhtml;jsessionid=15D857DF4B7588FB7A7C542BB8EA7A09
Etwas Kapton als Isolator dazwischen mit 0,1K/W. Macht 21,5 Kelvin Temperaturunterschied.
Man könnte den Wärmewiderstand des Viafelds noch verringern, wenn man stattdessen Kupfercoins einpresst.