o q é melhor?????
fechar em delta o strela??
qual tera mais força??
Montando um motor Brushless de cdrom /Guga e Carlos
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ron_van_sommeren
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Whether you use star or delta makes no difference, you can get exactly the same motor (Kv, Kt, Io, Ri) with both configurations: 17 winds in delta/triange is the same as 10 winds in star/wye (by factor 1.7 = sqrt(3) ). Wire
diameter has to be changed accordingly of course.
However, delta is a closed circuit all by itself, differences between the wound phases (#winds, wire-length or -diameter) may lead to differences in the voltages induced in the coils/phases. Useless circular currents will flow through the delta circuit, which leads to higher temperature and lower
efficiency.
Therefore: star (= wye = Y)
Higher efficiency does not only mean that the motor makes better use of the batteries' power, it also means the motor is able to handle a higher power input before hitting its maximum temperature mark.
An example:
Say the motor has an efficiency of 70% and it can handle 50Watt input. That means it can get rid off 0.3*50=15Watt excess heat. Now, by cramming in thicker wire, efficiency increases to say 75% (I'm a bit optimistic here). The motor's ability to loose those 15Watts has not changed (by radiation, convection and conduction). This means the motor now can handle 60Watt before it hits the 15Watt (0.25*60Watt) losses mark. An efficiency increase of 5% gives an increase in the power to weight ratio of 20%. That's why efficiency plays such an important role, in any motor design: efficiency governs maximum power.
diameter has to be changed accordingly of course.
However, delta is a closed circuit all by itself, differences between the wound phases (#winds, wire-length or -diameter) may lead to differences in the voltages induced in the coils/phases. Useless circular currents will flow through the delta circuit, which leads to higher temperature and lower
efficiency.
Therefore: star (= wye = Y)
Higher efficiency does not only mean that the motor makes better use of the batteries' power, it also means the motor is able to handle a higher power input before hitting its maximum temperature mark.
An example:
Say the motor has an efficiency of 70% and it can handle 50Watt input. That means it can get rid off 0.3*50=15Watt excess heat. Now, by cramming in thicker wire, efficiency increases to say 75% (I'm a bit optimistic here). The motor's ability to loose those 15Watts has not changed (by radiation, convection and conduction). This means the motor now can handle 60Watt before it hits the 15Watt (0.25*60Watt) losses mark. An efficiency increase of 5% gives an increase in the power to weight ratio of 20%. That's why efficiency plays such an important role, in any motor design: efficiency governs maximum power.
Vriendelijke groeten 
Ron
• homebuilding brushless motors •
Ron• homebuilding brushless motors •
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ron_van_sommeren
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Tom Cimato of www.maxcim.com motors on the star<>delta issue, third paragraph:
http://groups.yahoo.com/group/lrk-torquemax/message/9534
http://groups.yahoo.com/group/lrk-torquemax/message/9534
Vriendelijke groeten Ron
• homebuilding brushless motors •
Ron• homebuilding brushless motors •
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ron_van_sommeren
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[quote:1812101046="edfarina"]... I am developing a controller for engine without brush to place in a model average trainer, using a PIC16f628 microcontroller.[/quote:1812101046]Have a look at this excellent do-it-yourself brushless controller design discussion:
http://www.rcgroups.com/forums/showthread.php?t=200567
BLDC design discussion group
www.yahoogroups.com/group/osmc
Several diy brushless controller designs:
www.rcgroups.com/forums/showthread.php?t=140454
A 40V/400A design:
http://www.rcgroups.com/forums/showthread.php?t=200567&page=17&pp=50
http://www.rcgroups.com/forums/showthread.php?t=200567
BLDC design discussion group
www.yahoogroups.com/group/osmc
Several diy brushless controller designs:
www.rcgroups.com/forums/showthread.php?t=140454
A 40V/400A design:
http://www.rcgroups.com/forums/showthread.php?t=200567&page=17&pp=50
Vriendelijke groeten Ron
• homebuilding brushless motors •
Ron• homebuilding brushless motors •
[quote:8c10fa7295="edfarina"]Se não me falha a memória, no site do LEARJET INDOOR, tem um motorzinho 180 de briquedos, convertido para BL, dando 350g de empuxo...
Já um BL feito de CDROM (caprichado), eleva verticalmente um modelo 3D de 350g aproximadamente...[/quote:8c10fa7295]
creio que para conseguir estes 350 gramas de empuxo eu devo trocar os magnetos, certo? ou é possivel somente reenrolando?
Já um BL feito de CDROM (caprichado), eleva verticalmente um modelo 3D de 350g aproximadamente...[/quote:8c10fa7295]
creio que para conseguir estes 350 gramas de empuxo eu devo trocar os magnetos, certo? ou é possivel somente reenrolando?
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Julio Cesar
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[quote:10e278cec0="hate"]creio que para conseguir estes 350 gramas de empuxo eu devo trocar os magnetos, certo? ou é possivel somente reenrolando?[/quote:10e278cec0]
Para Direct drive tem que reenrolar e substituir os magnetos, mas se for reduzido você consegue os 350g sem a troca dos magnetos (optek).
Para Direct drive tem que reenrolar e substituir os magnetos, mas se for reduzido você consegue os 350g sem a troca dos magnetos (optek).
Júlio César
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Julio Cesar
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