Castle - Make A Special Edition Monster

[lutach]

Artur,

I sent you the e-mail with the 2 photos. Let me (us) know what you think of those controllers.

[GriffinRU]

Originally Posted by lutach

Lets assume you have a quad power board R1, would that make less then the 3.2W of dynamic loss? The controller will have more FETs and each one would be working less to make the same amount of power that a single or double power board controller would be. Another example which is completely off topic would be in car audio. I had a 4 woofer set up in my car and it was loud (Load enough to have neighbors complain that things were falling from their furniture's ), but then I went up 4 more for a total of 8 woofer wired for the same load to the same amp and it was blistering loud. Each woofer was getting less power from the amp, but they were putting out higher db at the same time. The design that I have in mind (Artur I will send you 2 examples via e-mail) will be a total of 240 small FETs with a datasheet rating of 10A each and they come in 30V and 60V. Each power board will have 80 FETs so 40 in the H-Bridge you mentioned in another post. I'm just throwing out ideas basically to see a rock solid controller that is better then a Schulze 40.160, but a tad smaller for around the same price.

We will continue next week-end, need to go.
Dynamic loss is fixed with fet, each fet has a capacitance in the gate (value dependant on temp, load...) to charge and discharge this capacitor requires energy, so more fet's more energy.
Conduction loss would be related to Rdon and more fet's lower value, so good thing, but as you can see you need to keep balance...

I will check e-mail later, and let you know.

Keep in mind TO-220's and D-Pak's are huge packages and can easily absorb ~1W without heatsink, but they are not as fast as smaller, tuned fet's.

Your Amp has a pretty sized heatsink, right :)

[lutach]

Originally Posted by GriffinRU

We will continue next week-end, need to go.
Dynamic loss is fixed with fet, each fet has a capacitance in the gate (value dependant on temp, load...) to charge and discharge this capacitor requires energy, so more fet's more energy.
Conduction loss would be related to Rdon and more fet's lower value, so good thing, but as you can see you need to keep balance...

I will check e-mail later, and let you know.

Keep in mind TO-220's and D-Pak's are huge packages and can easily absorb ~1W without heatsink, but they are not as fast as smaller, tuned fet's.

Your Amp has a pretty sized heatsink, right :)

Heat sink issues will be no problem as the design I have in mind will allow for a very good heat sink to be used without sacrificing size (Compared to much larger ESCs). Look at this article in Power Electronics Technology http://powerelectronics.com/thermal_...osfet_cooling/. The LFPAKs that I have been mentioning are being compared to the other package found on controllers such as the Schulze 40.160, Actronic 120, Jeti SPIN170-300 and the ones I'm having made. This article is saying things like, "This fact also opens the possibility of further reducing the pc board space occupied by the power MOSFETs by using physically smaller devices and placing those devices closer together. To investigate this possibility, another simulation was carried out where each pair of D2PAK MOSFETs in the H-bridge circuit was replaced with three LFPAK devices.

The LFPAK package is much smaller than the D2PAK, occupying the same pc board footprint as the familiar SO-8 package. However, unlike the SO-8, the LFPAK is a true power package that incorporates a bottom metal contact, which provides an effective heat path out of the device. There is an additional thermal pathway between the top of the device silicon and ambient through the top part of the encapsulation.

Although the LFPAK solution increases the total number of power packages used, the total board area occupied by this solution is significantly less than for the D2PAK case because the LFPAK package is much smaller than the D2PAK." and "In the last few years, there have been significant advances in the packaging of MOSFETs, including the introduction of the power SO-8 package. Bottom-side cooling can now be used successfully to transfer heat through the pc board, even when smaller power packages like the LFPAK are used in place of the D2PAK. The package on-resistance and inductances for these smaller package types are also significantly lower. The total losses in a system caused by these sources are therefore reduced significantly, even with the additional devices needed when using the smaller package types in place of larger MOSFETS.

The greatest advantage when switching from D2PAK to LFPAK is the resulting reduction of board space occupied by the MOSFETs, since pc board top copper is not needed to radiate heat. The smaller MOSFETs can be placed closer together, and the previously occupied board space is made available for other components." The components that I have in mind though are much smaller measuring 3mm Length x 2mm Width X 0.8mm height. If this works, it should make a very powerful controller.

Originally Posted by GriffinRU

Very nice post, Five-oh-joe

More fet's bigger foot print more surface area to dissipate heat, more overall losses...
Fet's driver need to be very nice or need to be on each FET's board, but try to sync them...possible.

Let's do quick theoretical calc, if you can drive fet's as fast as fet can switch (non-real) then 300 fet's you meant total, so 50 fet's per leg/100 fet's per phase. Dynamic losses would be ~10W on fet and ~10W on diode, check attached image. With 3 phases your loss would be ~60W just for switching at 15kHz PWM, that would cook ESC pretty fast without proper heatsinking, by the way can be a nice heater :)

It would be nice to keep dynamic losses matched to pcb heat dissipation capacity.

I am pretty sure, Patrick can add/correct my post if required.

Thanks Artur!

Lutach- sounds like you got some serious stuff planned. I haven't read through all of your posts yet, so I'm a bit behind. It's nice to have consumer ideas thrown into the mix though!

So what's the difference between the SO8 FETs and the DPAKs? I'm guessing DPAKs have a metal type housing whereas SO8s are still that resin/plastic?

[Pdelcast]

Originally Posted by lutach

LFPAK --

I've found that LFPAKs are inferior to the SO8-FL package (flat lead, leadless SO-8 -- or PowerPAK SO-8 depending on who makes it) because they still have wire bonds on the source leads, where the SO8-FL has copper clips. The SO8-FL package also dissipates heat much better than the LFPAK, which is kind of a half SO-8, half DPAK package.

The DPAK doesn't take as large a die as either the LFPAK or the SO8-FL, and it has about 2 milliohms of package resistance -- making it not very well suited for 30V applications.

[lutach]

Originally Posted by Pdelcast

I've found that LFPAKs are inferior to the SO8-FL package (flat lead, leadless SO-8 -- or PowerPAK SO-8 depending on who makes it) because they still have wire bonds on the source leads, where the SO8-FL has copper clips. The SO8-FL package also dissipates heat much better than the LFPAK, which is kind of a half SO-8, half DPAK package.

The DPAK doesn't take as large a die as either the LFPAK or the SO8-FL, and it has about 2 milliohms of package resistance -- making it not very well suited for 30V applications.

Will the LFPAK work better in a higher voltage controller? I do own a controller that uses 30V LFPAK MOSFETs, rated for 6S lipos and it works pretty well. It didn't get hot at all for the 5 minutes I used it. I was impressed by that as the heat sink on it looks really crappy. If you made a HV car controller that looks like the HV and SHV controllers using the LFPAK MOSFETs would that work? I like the way the HV controller looks and I have my HV110 that I still need to send in if you need a guinea pig. I know the LFPAK have some 75V MOSFET and that could even make a possible 16S controller.

Now for my other question I posted before.

Being able to drive all the MOSFETs (keep this in mind), would a controller with 240 MOSFETs total or 80 per phase, but 40 in the H bridge config. work less to make the same amount of power as one with less MOSFETs?

Now, this controller don't need to be all that small. Something that is smaller then the Schulze 40.160 will do . I know more FETs and other components will add to the cost, but that's only if parts are being bought from Digi Key, Mouser and any other catalog distributors so lets keep that on the side for now. I'm just trying to get a rock solid controller. I even went as far as contacting and sending 1500 MOSFETs to a company in China to make me a 15S car controller and they never did one so you know the problems they are facing. All they make is Airplane and Helicopter controllers. I know they are using the Atmel's ATMEGA8L-16AU MCU and some car controllers that I have uses the same MCU. My guess is they are still having trouble with the software.

[Pdelcast]

Originally Posted by lutach

I even went as far as contacting and sending 1500 MOSFETs to a company in China to make me a 15S car controller and they never did one so you know the problems they are facing. All they make is Airplane and Helicopter controllers. I know they are using the Atmel's ATMEGA8L-16AU MCU and some car controllers that I have uses the same MCU. My guess is they are still having trouble with the software.

If they are using the Atmel part, they are likely using either stolen Jeti software, or stolen Schultze software. Both companies had their software compromised and copied in China. Both companies have tried unsuccessfully to stop imports of controllers with their stolen software. (I can't imagine how much money it would take to go after these companies... they setup shop and only do business out of Hong Kong where they are shielded by the Chinese government.)

So it's unlikely that they have any resources to modify the software for RC car use.

It's funny, most of the controller coming out of China identify themselves as a Jeti-18 (regardless of the type/size of the controller) when connected to Jeti's field programmer. Several others ID themselves as Schultze. I've yet to see a Chinese or Taiwanese controller that has decent software that was not stolen from another company.

[lutach]

Originally Posted by Pdelcast

If they are using the Atmel part, they are likely using either stolen Jeti software, or stolen Schultze software. Both companies had their software compromised and copied in China. Both companies have tried unsuccessfully to stop imports of controllers with their stolen software. (I can't imagine how much money it would take to go after these companies... they setup shop and only do business out of Hong Kong where they are shielded by the Chinese government.)

So it's unlikely that they have any resources to modify the software for RC car use.

It's funny, most of the controller coming out of China identify themselves as a Jeti-18 (regardless of the type/size of the controller) when connected to Jeti's field programmer. Several others ID themselves as Schultze. I've yet to see a Chinese or Taiwanese controller that has decent software that was not stolen from another company.

That sucks. So did Jeti and Schulze forgot the protect their software ? This company promised me they were going to do it and now it is basically tha, a promise. I might just get the controllers done with what ever software they have and use them is a car with mechanical brakes .

[Pdelcast]

Originally Posted by lutach

That sucks. So did Jeti and Schulze forgot the protect their software ? This company promised me they were going to do it and now it is basically tha, a promise. I might just get the controllers done with what ever software they have and use them is a car with mechanical brakes .

No, they didn't forget to protect their software. The ATMega software protection can be compromised.

[lutach]

Originally Posted by Pdelcast

No, they didn't forget to protect their software. The ATMega software protection can be compromised.

Good thing the quality of Jeti and Schulze are top notch compared to the Chinese version.

[Pdelcast]

Originally Posted by lutach

Will the LFPAK work better in a higher voltage controller?

I don't mean to say that the LFPAK isn't a good package - - it is one of the better ones on the market. It's just that all of the testing we have done has showed that it is inferior to the SO8-FL package, and the LFPAK doesn't have a price advantage (in fact it is usually more expensive) over the SO8-FL.

Look at Infineon's "Super-SO8", On Semi's "SO8-FlatLead", Fairchild's "Power 56", or Siliconix' "PowerPAK SO-8" package. They are all essentially the same package, are reasonably priced, and perform very very well.

[lutach]

Originally Posted by Pdelcast

I don't mean to say that the LFPAK isn't a good package - - it is one of the better ones on the market. It's just that all of the testing we have done has showed that it is inferior to the SO8-FL package, and the LFPAK doesn't have a price advantage (in fact it is usually more expensive) over the SO8-FL.

Look at Infineon's "Super-SO8", On Semi's "SO8-FlatLead", Fairchild's "Power 56", or Siliconix' "PowerPAK SO-8" package. They are all essentially the same package, are reasonably priced, and perform very very well.

How well would a bunch of "Siliconix's PowerPAK 1212-8 Package" MOSFET (Keep in mind, being able to drive a lot of them) do in a ESC designed for car that can do 12S lipos? I'll bet you can fit a lot of them in a controller similar to the HV. Is there anyway you can treat us RC-Monster followers to a mother of all controllers "RC-Monster Edition"? I know you play with a lot of designs. I can't imagine you just build the products we see in you website. You probably have a 12S controller now that can handle spikes of 200A that you are playing with and not telling us.

[Pdelcast]

Originally Posted by lutach

How well would a bunch of "Siliconix's PowerPAK 1212-8 Package" MOSFET (Keep in mind, being able to drive a lot of them) do in a ESC designed for car that can do 12S lipos? I'll bet you can fit a lot of them in a controller similar to the HV. Is there anyway you can treat us RC-Monster followers to a mother of all controllers "RC-Monster Edition"? I know you play with a lot of designs. I can't imagine you just build the products we see in you website. You probably have a 12S controller now that can handle spikes of 200A that you are playing with and not telling us.

Why the 1212-8 package? The footprint to silicon ratio is better on the larger Powerpak FETs...

I am playing with a version of the Monster that is stackable, and can use 30, 40 or 60V FETs. I already said that earlier...

[BrianG]

Originally Posted by Pdelcast

...I am playing with a version of the Monster that is stackable, and can use 30, 40 or 60V FETs. I already said that earlier...

I want a double stacked version using 60v FETs please. And leave out the UBEC.

[lutach]

Originally Posted by Pdelcast

Why the 1212-8 package? The footprint to silicon ratio is better on the larger Powerpak FETs...

I am playing with a version of the Monster that is stackable, and can use 30, 40 or 60V FETs. I already said that earlier...

I just had an idea that the more FETs would be better? The 1212-8 is roughly half the size of the larger PowerPak and I keep thinking the more the better as each FET will work less to produce the same power as less FETs. I know I'm not an engineer and what we think off might be possible in our heads, but not in true life application. But since you are working on the stackable Monster, when will the HV one be available? Will you be having other guys put the controller to the test or will it just be team drivers?