is it really hard to build a higher watt esc?

[Hombre]

i am wondering why we dont have esc's to match the developement of electric motors?

[David Hajj]

Hombre,

Time and money but a market has to be there in numbers to justify the development and startup production cost. Along with new supplier lines, material supply contracts, pricing on and on. Andy knows this better than I do. A lot of the maket is in flux now.

It's coming but just not all at the same time. In fact it's just around the bend for ESC's.

David

[Slick1]

I share your concern. And I don't "feather" the throttle, for fear that doing so will smoke the ESC. I basically use it as an on/off switch. The ESC is the most expensive but the least dependable link in the chain.:(

[Twinpowered]

The problem lies in reliability. I'll try to explain it as simple as possible:

Your voltage is fixed, for safety reasons. So more power comes from more amps. More efficient FET's (the parts that switch the power) are one way to raise that capacity, but it's not enough to outpace the development of motors. So at this moment, you can only increase the ESCs capacity by raising the number of FET's. But more FET's increases the risk of failure: your MTBF will drop rapidly as the FET count is rising. Also, the FET's (along with the PCB) are the most expensive parts of an ESC.

Going further along this route: an ESC with twice the capacity will cost you almost twice the amount of money, with a failrate that's almost twice as high it currently is. Do you really want such an ESC? And most important: would you want to be the manufacturer of such an ESC?

[AndyKunz]

Actually, it's more than twice as high a failure rate. The FETs are the only devices which are operating on any "real" sort of failure curve - almost everything else is so within specs that there is no component aging.

The problem is that the one component type which is stressed is also the one of which there is the most number.

The good part is that doubling the FETs at the same system load reduces the individual component stresses to about 25% of what they were before the doubling of FETs. You _do_ get a net increase in reliability, but only if you don't increase the current that the system has to deliver.

Andy

[Hombre]

Thanks guys, learnt something new again, so to me thats seem that nitro / gas is almost at there limit with only a little tweecking, while electric is far away from being at there best?

"The good part is that doubling the FETs at the same system load reduces the individual component stresses to about 25% of what they were before the doubling of FETs. You _do_ get a net increase in reliability, but only if you don't increase the current that the system has to deliver"

would it be possible to run two esc in series?

regards
pete

[AndyKunz]

No. They would confuse each other.

Electrics have far from reached their potential.

Andy

[Twinpowered]

Some ESCs offer the possibility to stack them. They've got a connection between them for synchronisation. But most of the time it's cheaper to simply buy a more powerful ESC.