6-ch High Current driver

hey i wanted to get some input on this little find today, i thought this would be right up the repraps ally for handy parts. http://www.seeedstudio.com/depot/images/product/6ch1x3.jpg

i do like this find and i will order 1 has soon has i have the funds to do so.

it will take up too 30v at 5A on each channel,

do you think this could help allot of people out, i think it would be safer too seeing how it is on the supply side for the heaters and would be far better off if there was a short.

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[mike-mack.blogspot.com]

The components used on that board look very interesting - diagnostic output with the ability to detect short circuit, open, over temp. I wish they had provided connections to the diagnostic pin on the devices.

if there was enough demand for it here, i think it could happen, i do like this board allot.

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[mike-mack.blogspot.com]

The 5A rating appears to be for unrealistic. The recommended operating conditions portion of the spec sheet for the IPS6041G (the SO8 part shown in the picture you've linked) lists 1.6A continuous drain current, with a max switching frequency of 3.5kHz. The switching frequency is high enough to be useful for PWM heater control, but some of the current controllers may be using frequencies much higher than that, so you'll need to be aware of that.

oops here is the proper link http://www.seeedstudio.com/depot/6ch-high-current-driver-1x3-kit-v1-p-792.html?cPath=170_173&zenid=54eae73f5681f53cd85deed4a5fa6a13

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[mike-mack.blogspot.com]

Imho:
High side switch means it switches the positive rail, which is sensible different expression of "high current switch".
Because 5A rating in not really high and is something most fets will do, without sink, in "still air". Also to note this is probably the math about the max point and max operating temp before shutdown, so the datasheet at page 2 gives recommended operating conditions for G version at 1,6A which is the realistic one for the huge values of rdson and thermal to ambient. Because running fets 0.1C close to their meltdown temperature may not be so "cool". To make bacon and eggs we use a frying pan, dont need fets for that.

Imo, the switching isnt a issue untill the heated bed problem. When one wants a good powerful heated bed to be fed from a DC, now then the switch fet becomes a problem as it would need to switch alot of current, this time would be "high current" even if its a low side switch, as in normal mendel. Low dc isnt quite optimal for high power stuff because of the high Amps involved. For a 200W heated bed @12V it points 16.7A. Ofc 100W would be half but would probably be a little slower in performances. And to realistically switch 9A, it would prefer something like a 20A rating at least, for a good component life. Again its the rating where without sinking or venting in "still air", the disipation temp touches the max oper temp and internal shutdown is about to be triggered.

We dont want to design anything that will be, under normal conditions, anywhere close to that. The difference is the "safety margin" of the design. Put some cheap parts close to their breakdown points = you get a device which will break and the user will have to change in 1-2 years. Put a good margin there between the components and their max points and overkill every aspect, and that device will last a very long time and the company will go bankrupt because after all users bought one unit, no1 will need to buy additional ones. Since competition depends 90% of price, all products will tend to be cheapest and will tend to break sooner rather than later. That would be one of capitalism's design flaw haha.

As usual, I will stand corrected if anything i said is wrong. After all, I am dumb enough to make mistakes, this was proven true enough times in the past and will be, no doubt, proven again, rather sooner than later.

This should double checked etc. It is from an excel, couldnt possible link all items, i dont remember details or why i wanted the items for, and mistakes can be there, in formulas etc, in part or in all of it but some math shows like that to me:
NAME // VNP35N07 // MTP35N06 // IRF2903ZPBF // IRFZ44N // STP55NF06 // IRL3803 // IPS1021 // IPS1011
Rds(on) @25 // 0.028 // 0.050 // 0.024 // 0.175 // 0.018 // 0.006 // 0.025 // 0.013
Max temp T // 150 // 175 // 175 // 175 // 175 // 175 // 150 // 150
R-thj-amb // 62.5 // 62.5 // 62 // 62 // 62.5 // 62 // 50 // 50
Pwr disipated @25 // 125 // 90 // 290 // 94 // 110 // 200 // 25 // 25
I max // 35 // 30 // 260 // 49 // 50 // 140 // 35 // 85
I estimated // 20 // 20 // 20 // 20 // 20 // 20 // 20 // 20
Pwr disipated on fet // 11.2 // 20 // 9.6 // 70 // 7.2 // 2.4 // 10 // 5.2
Rds(on) @max T // 0.102 // 0.100 // 0.004 // 0.039 // 0.044 // 0.010 // 0.020 // 0.003
No sink pwr // 2.40 // 2.80 // 2.82 // 2.82 // 2.80 // 2.82 // 3.00 // 3.00
Amps w/o sink // 4.85 // 5.29 // 25.65 // 8.49 // 7.98 // 16.63 // 12.12 // 29.44

i do personally find this board interesting, and intriguing enough for me to buy, i also think that it would be a good thing in time to switch to high current switching, though i know it is more costly.

in time i will fiddle around with this board maybe it will be useful maybe it wont, i wont find out until i try.

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[mike-mack.blogspot.com]

Yup true. The board looks nice and all, and i am not trying to convince you of anything, just answering like an opinion request.

Good luck testing (i really hope it will do the trick) and let us know how it goes.