Frank, My speed controller is rated at 24v, 25amps x 2 i.e. two motors both able to draw a maximum continuous current of up to 25amps. Currently I'm using 12v motors drawing, roughly 15 amps so my speed controller is comfortably within tolerances. I'm wondering what will happen if I over-volt my motors to 18v - still comfortable for my ESC. The motors have ducted cooling fans and the ESC has it's own cooling fan too.
On Oct 5, 1:32 am, Frank Pittelli <frank.pitte...@gmail.com> wrote: > Pureteenlard wrote: > > I need to know because my speed controller is rated well above 15 amps > > but if I overvolt my 180w motors to 18v will the current rise too or > > just the power? > > There are basically two items you need to focus on: Voltage and Heat. > > The FETs used in the ESC have a maximum voltage rating and a maximum > amount of heat they can dissipate per unit time. They usually don't > tell you the heat rating directly, instead they tell you the amount of > power (voltage times amps) it can deliver to the motor. (They take the > efficiency of the ESC design into account and usually tell you what size > heat sink is needed or the amount of air in CFM to maintain the maximum > continuous power output.) > > You should *NOT* exceed the maximum voltage rating without expecting it > to fail because the parts being used simply can't handle it. For > example, an ESC designed for an R/C car may have a maximum voltage of > 12v and a power rating of 500 watts. In that case, even if you are well > below the power rating, you may still blow the ESC if you trying pushing > 18v through it. > > You *CAN* exceed the maximum power rating if you use a large cooling > system (e.g., bigger heat sink, more fans, liquid cooling, etc). The > added cooling removes the excess heat and allows the FETs to operate a > bigger load without failing. Strictly speaking, the higher operating > temperatures and loads will in fact reduce the overall lifetime of the > FETs, but for our purposes (operating a couple dozen hours per year) > that's not a major problem. > > Frank P. --~--~---------~--~----~------------~-------~--~----~ You are currently subscribed to the "R/C Tank Combat" group. To post a message, send email to rctankcombat@googlegroups.com To unsubscribe, send email to rctankcombat-unsubscr...@googlegroups.com Visit the group at http://groups.google.com/group/rctankcombat -~----------~----~----~----~------~----~------~--~---
