New 100a reversible car esc on hobbycity
 

http://www.hobbycity.com/hobbycity/s...idProduct=8993

Hobby King Brushless Car ESC 100A w/ Reverse

http://www.hobbycity.com/hobbycity/s.../Quik-100A.jpg

Features:
Full protection feature including low voltage, over-heat, throttle signal lost, startup
protection and self-check.
Compatible with sensorless brushless motor.
Excellent startup performance, linear and quick throttle response.
Supports highest motor speed 240,000RPM(2 poles), 80,000RPM(6 poles) and 40,000(12 poles).
Easy to configure with program card.
System can automatically detect throttle neutral point, and neutral range is adjustable.
Three work modes for different environments.
4 step reverse force adjustment
5 step start force adjustment.
3 step brake force adjustment
5 step drag brake force adjustment,
4 step initial brake force adjustment.

Specification:
Input voltage: 5V-17V (support 2-4S lithium batteries)
Cont. Current: 100A
BEC output: 3A /5.5V (switch)
Size( length X width X high): 47x41x29mm
Weight: 95g

Price - $60 bucks

Stock - 44 on sunday morning


Looks like a mamba max alternative. It has a bec, which might be disable/ble for more power. The bec might also be like the mmm where it doesn't help... I bet this would be pretty nice low-cost alternative in a 2wd or a light 4s buggy setup.

Here it is on Ebay, http://cgi.ebay.com/Viverrine-100A-B...3A2%7C294%3A50 It looks like it could work.

That one looks about the same but it only has 1 capacitor? Maybe hobbycity changed it/them.:neutral:

The description is very similar but the picture throws me off...
http://i9.ebayimg.com/01/i/001/23/fc/6f50_1.JPG

Yeah, hard to say. But the fact that it's rated to handle 4s, at 60 bucks ,makes it something that needs to be tested.

There are a few companies that makes this ESC. I was going to test this one, but it's only a 4S capable ESC. I asked for a higher rated ESC, but only the bigger version are available. They were going to have only one cap, but I explained how dual cap would be better incase one fails. The bad this is that Hobbycity could've included the programmer at no extra charge. I like this factory as they have not used the software that my ESCs comes with. I was also going to test a 30A they have with my motors, but it's a bit on the big side.

I wonder if everything is rated for 25v and you could get a 5s setup in there after disabeling the bec. Think it's possible?

There's only one way to find out :lol:.

looks alot like a gtb...

I just saw it on there today while brousing their wed site(very nice if you ask me). Nice looking product. Very good find!

i saw that last week as well. looks like a nice product, only reason i didnt post about is because i figured someone else would. i must be psychic.

But it's sensorless. It very well could have been modeled after a GTB though.

You won't catch me running one of these (unless I got it for free). It's likely to have no warranty or customer support, so if you burn out the first and buy another, you are already at the price of a Mamba Max. And we know CC has great CS.

You might be surprised if it's a good ESC. I'll bet they'll have the same good start up as the ones I have. As for warranty and customer support, it's up to the place that will be selling them to provide and yes, it would suck to have to send it over seas for that. Who knows, maybe somebody in the US will carry them at a similar price.

Meh, it has a fan. 'Nuff said.

Castle Mamba Monster, Castle Mamba Max Pro, Tekin RX8, Losi 10th and 8th scale ESC, Hobbywing (Speed Passion and Orion), Novak, Traxxas, Ko Propo (Orion), Tamiya, Quark Plasmas and a few others that I might've missed. Brian, which one do you use :lol:.

Let's see:

- Two MMMs: yes, I do use the fans. But I would rip them out in a heartbeat if it wasn't for that warranty issue. :no:
- One HW80: no fan.
- Four MM's: no fans.
- Two Quark 125b: no fans.

:lol:. Just messing with you Brian. I spoken with a few knowledgeable people and they said is not that difficult to make a very strong ESC that would stay cool without fans (Easy for them to say, some work for the largest EMS companies in the world). One of those people saw a design I have in mind and it was exactly what he was talking about. Now all of them said if all the MOSFETs are saturated (I've heard this before, but still having trouble figuring out what it actually means. All know is if a driver can switch a lot of MOSFET, why not make a humangodango of a ESC, people will buy the them if one builds them) it would definitely handle what ever R/C motor available. I'm actually testing something out to see if they are right and from the initial test, I think they might be specially with a driver that I was told wouldn't be able to switch all the MOSFETs. I wish I knew what I was talking about, but I don't. So feel free to fill my head with goodies.

Saturating a MOSFET simply means driving the gate with enough voltage that the drain and source has as little resistance as possible. An "ideal" FET would have infinite gate resistance, zero gate capacitance, zero on-resistance, and infinite slew rate. No losses means 100% efficiency.

Anyway, less resistance equates to less voltage drop, which equates to less power wasted as heat on the FET for a given current. However, aside from an FETs rdson value, it takes time (albeit small) from when the FET turns off to fully on, and back again. This is called the slew rate and is measured in volts per second (or milli-second). During that time, there is variable "resistance" (increasing as the FET approaches "off", decreasing as it approaches "on"). Since a PWM signal switches on/off many many times per second, it makes sense that at those times is where you have the majority of the losses. OK you say, so why not simply reduce the on/off cycles? Well, you can, to a degree, but then you have motor inductance and the role it plays with the PWM "A/C" to worry about.

Paralleling enough FETs reduces the total rdson value and also reduces the voltage drop during the on/off cycles. If a FET can be totally saturated AND have a very very fast slew rate, losses are greatly reduces. Then, the FET current rating is pretty much limited by the package wiring.

I hope I explained that for you; I tend to ramble. :oops:

Info like this is like giving a chocoholic free chocolate for life :lol:.

mmmm, chocolate. :love:

Uh, yeah, anyway... I'm sure there is more to the story, but you can ask your engineer friends for all the sordid details. It's been a loooong time since I've done any kind of tinkering with FETs...

The problem is all the engineering lingo and complexity that messes my poor non engineer brain :lol:. One day who knows, I might see the design I have come true.

lol, let's hope it is smaller than the average office desk though. :wink:

One of the designs for a 8th scale ESC has a MOSFET (Power Board) board measurement of 44mm (length) x 33mm (width) with 10GA wires. With the FET 30A rating it gives about 180A or 360A if double MOSFET board is used. I have other more powerful designs, but they are somewhat complex.

Sorry lutach, traxxas has an option for a fan, but its not mounted or included with the esc

My fault, I gave my Traxxas away.

Anyone tested one of these ESCs yet?

Those are similar to the older 60A and 35A ESCs, right? I've got a pair of the 60A Marine ESCs (same thing as the land ESC but sealed up and water cooled) and they've been excellent so far.

I read a few of the reviews on te esc and they say that it will not work with spektrum radios, as it shuts down the motor at full throttle. Is this because the spektrum rx needs a higher voltage to stay on, and the bec on the esc can't keep up at full throttle?

It could be a switching BEC problem. Someone in the Brasilian forum got one and he said it works good.

Does it have a switching BEC? Would make sense if it was linear and running on 3s+. Either way, an external BEC solves that problem. Although, sometimes simply adding a 1000uF+/10v cap on an unused receiver port provides enough buffer for momentary high servo loads.

I still don't get why you hate fans, could you explain it please? :lol:

He just wants stuff to be designed to handle the load without needing forced airflow. If the fan breaks (and they do) the esc should be able to handle it. No too much to ask, IMO.

Not only do I want it, I demand it! :lol:

There is a time and place for everything, but fans do not belong in R/Cs unless they are being run with improperly chosen components and/or extreme running conditions (and that could be cured by component upgrade). Bottom line; if things run hot and you don't want to sacrifice speed/performance, get better/more suitable parts.

Like anything else, if you run things to just below their breaking point, there is no room for error. All it takes is maybe a little over-engineering and you'd be golden. This hobby is definitely not one of those places where you can cheap out and expect great results.

Schulze L, XL, XXL, Jeti SPIN200, SPIN220, SPIN300, Kontronik Jive and not 100% sure if MGM is reliable without a fan :lol:. I've been told by a few that to make such a ESC it would cost beyond what most in the hobby is willing to pay. There are awesome materials available now that are being mostly used by the world's military. Maybe all we need is a thermal engineer to come up with a dynamic new way to cool these amazing little devices. I have my ideas (GriffinRU is very knowledgeable on this matter) and so do most in this forum, but we can't make it and have to rely on the current manufacturers to make them for us lol. Also, with most ESC that doesn't use a fan, you better have room in your vehicle for it as they can be a little on the big side.

Pah, even my Quark 125B's run cool, and they are known for running warm. Just a little added heatsinking and some decent airflow are all that's needed. After all, these are moving vehicles and movement creates airflow.

All it takes for a cooler ESC is better FETs (easier said than done, eh?). Something with less rdson, and more importantly, a higher slew rate. I don't think it will be too long before this is a reality given the advances in technology and manufacturing processes. Heck, you could just take today's FETs and stack them without any heatsinking. Just doubling the count would reduce the heat by half for a given current. So, instead of coming up with newer FETs that have more ideal specs, why not simply use more of the ones we already do have? Some of them (like on the MM/MMM) are small enough to piggy back easily. Might drive the cost up a bit, but if bought in bulk, they would be cheaper than getting a more advanced FET.

I like stacking power boards lol. I was told by the manufacturers that stacking would cause excess heat, well they are learning from a non engineer lol. All the stacked ESCs I have have shown much improvement and run much cooler then the single power board version. I got to see if it's possible to triple of even quadruple stack them lol. Crap why stop there, could even make a tower of terror lol.

Heat buildup in a stacked setup is a poor excuse. Just do something like what CC does on their HV110.

Is it possible to buy and modify an existing esc by just stacking fets? Say I got this 100a esc, took off the heatsink, then stacked another layer of fets on there, then properly re-attached the heatsink. Would I see lower temps and higher amp handling capability?

Or the dual-heatsink MGM's. Which in my experience run great without fans. :yes: