Making an esc better?

Griffin,

Two mamba boards in parallel? Would this be similar to just soldering on a bunch of FETs in parallel to those already on the board? Forgive me if that is an ignorant question. It's just that I was thinking about it as I was sitting in court today. I wondered what the effect would be if I just soldered a bunch of FETs in parallel to those already there. Wouldn't that almost double the esc's ability to handle current? If this is just plain stupid, let me know. If it is a possibility, let me know that too. I'll source some FETs and maybe get lucky.

I don't know if this tells you anything, but I got back a couple of MMs that I sent to Castle for repair. The repair receipt says that the cause of the failure was "FET Failure." It also says, parts used:

6-BSC022N
2-F320
6-ISL6700
2-BAT54A
2-TL750
4-BAW56LT1
2-LM2665
2-LM3394

Obviously (I think) the prefix number preceeding the hypen is the number of components used to repair my two escs, but the rest of the stuff might shed light to someone that knows what they are doing.

[zeropointbug]

6s...300A....:027:

How are you going to go about doing this? (package setup) What kind of FET's are you going to use?

GriffinRU: If you have look at my Quark case design, I am wondering how cooling all FET's very well will change current capability? I know it will probably ALLOW it to run to it's rated continuous current (most likely), do you think it could run a 2250 (with a bunch of added caps) in say a heavy 1/5, 1/6 scale on-road car?

[GriffinRU]

Originally Posted by zeropointbug

6s...300A....:027:

How are you going to go about doing this? (package setup) What kind of FET's are you going to use?

GriffinRU: If you have look at my Quark case design, I am wondering how cooling all FET's very well will change current capability? I know it will probably ALLOW it to run to it's rated continuous current (most likely), do you think it could run a 2250 (with a bunch of added caps) in say a heavy 1/5, 1/6 scale on-road car?

I am looking at IRF1324S-7 with 12 FET's total.

If you can keep temp low and under control then I do not see any problems with driving any scale model. But there is one thing which you need to consider, with every today's speed controller (with SO/SOIC) only one side has good heatsink, that means that only these FET's can be used in calculation for rated power dissipation (at elevated temp) and use derating factor as well. So if your quark has enough FET's to dissipated power of losses associated with 2230 motor at your working temp, then you should be Ok, otherwise that's would be your limiting factor.

[zeropointbug]

Originally Posted by GriffinRU

I am looking at IRF1324S-7 with 12 FET's total.

If you can keep temp low and under control then I do not see any problems with driving any scale model. But there is one thing which you need to consider, with every today's speed controller (with SO/SOIC) only one side has good heatsink, that means that only these FET's can be used in calculation for rated power dissipation (at elevated temp) and use derating factor as well. So if your quark has enough FET's to dissipated power of losses associated with 2230 motor at your working temp, then you should be Ok, otherwise that's would be your limiting factor.

Yes, that's what I mean. It should keep all FET's very cool... the top FET's will have copper heatspreader to case, and the bottom FET's will be directly attached to case, it should work great!

I really am excited to see what comes out of your esc's for performance. What is the bigger problem then? -Getting the heat away from the FET's? -Or the number of FET's handling the power?

430A current capability, that's impressive!

[GriffinRU]

Originally Posted by AAngel

Griffin,

Two mamba boards in parallel? Would this be similar to just soldering on a bunch of FETs in parallel to those already on the board? Forgive me if that is an ignorant question. It's just that I was thinking about it as I was sitting in court today. I wondered what the effect would be if I just soldered a bunch of FETs in parallel to those already there. Wouldn't that almost double the esc's ability to handle current? If this is just plain stupid, let me know. If it is a possibility, let me know that too. I'll source some FETs and maybe get lucky.

I don't know if this tells you anything, but I got back a couple of MMs that I sent to Castle for repair. The repair receipt says that the cause of the failure was "FET Failure." It also says, parts used:

6-BSC022N
2-F320
6-ISL6700
2-BAT54A
2-TL750
4-BAW56LT1
2-LM2665
2-LM3394

Obviously (I think) the prefix number preceeding the hypen is the number of components used to repair my two escs, but the rest of the stuff might shed light to someone that knows what they are doing.

Thank you, I will check on parts...
As far putting FET's on top each other, you can do that, but MAMBA MAX ESC is not the best one to try that. I need to do some homework to understand why they didn't install resistor in series with FET's gates, but that might be just mistake or trick which I need to find out. If you add more FET's then you definitely need to add resistors and maybe replace boost caps. Another thought what is working great with TO-220/D2-pak packages doesn't work great with SOIC/SO-8, I am afraid that in addition to soldering you need to use some bonding compound to hold chip in place and provide good heatsinking.
And, fundamentally, YES it would increase current handling and decrease internal resistance.