killer deal on irfb4110pbf

[bobmcree]

i posted in another thread you might not be watching that my favorite fet vendor http://www.irtronix.com contacted me and they have some of the 100v 5 milliohm 180A (interested?) IRfb4110PBF FETS for $2.50, which is less than half the price elsewhere if you can get them. i got mine, and they just have a couple hundred left, so jump on it!!!

 

[fechter]

Doh! now you tell me.

Digikey finally got some stock, but they're quite a bit higher.

 

[xyster]

I couldn't find it using their search:
http://store.irtronix.com/search_adv.asp

do you have a direct link?

 

[bobmcree]

they did not show up online. i only found out they had them by talking to them on the phone when they called about my credit card order for some other parts.

 

[D-Man]

Is the ground shipping really $ 33.00 as listed or what? Wouldn't be much of a bargain if you have to pay that.

 

[bobmcree]

i have been buying from them for years and i have never paid that much shipping but i am in the western us., as they are.

i just bought 50 and shipping was $9.98. if i paid digi-key's prices the fets would have been $200 more, so even with $33 shipping it would be a bargain.

 

[cadstarsucks]

STP120NF10
Price:
(USD)
1 - 50 : 2.0200
51 - 200 : 1.3000
201 - 450 : 1.0600
451 - + : 1.0100

Hope this helps

Dan

 

[nemo]

i have been buying from them for years and i have never paid that much shipping but i am in the western us., as they are.

i just bought 50 and shipping was $9.98. if i paid digi-key's prices the fets would have been $200 more, so even with $33 shipping it would be a bargain.

IF ANYBODY IS INTERESTED in IRFB4110 and is resident in the UK let me know. We can split the shipping cost. I'll order/pay and than re-post them in the UK.
Thanks, Nemo

 

[bobmcree]

STP120NF10
Price:
(USD)
1 - 50 : 2.0200
51 - 200 : 1.3000
201 - 450 : 1.0600
451 - + : 1.0100

Hope this helps

Dan

those devices have more than twice the on resistance of the 4110

 

[cadstarsucks]

STP120NF10
Price:
(USD)
1 - 50 : 2.0200
51 - 200 : 1.3000
201 - 450 : 1.0600
451 - + : 1.0100

Hope this helps

Dan

those devices have more than twice the on resistance of the 4110

True, but that is a regular price, not a surplus lets get rid of them one.

Dan

 

[bobmcree]

STP120NF10
Price:
(USD)
1 - 50 : 2.0200
51 - 200 : 1.3000
201 - 450 : 1.0600
451 - + : 1.0100

Hope this helps

Dan

those devices have more than twice the on resistance of the 4110

True, but that is a regular price, not a surplus lets get rid of them one.

Dan

i don't see your point. irtronix is a reputable vendor of ir parts and there is no reason they would be getting rid of the 4110s as surplus. the devices you are suggesting are like saying a volkswagen is cheaper than a ferrari. yes it is, but so what?

 

[cadstarsucks]

i don't see your point. irtronix is a reputable vendor of ir parts and there is no reason they would be getting rid of the 4110s as surplus. the devices you are suggesting are like saying a volkswagen is cheaper than a ferrari. yes it is, but so what?

It is easier to replace two volkswagons than it is a ferrari. Especially when the ferrari dealership has closed down.

They seem more like a Mouser of Digikey wannabe from the look of the stock qtys on hand.

Being actually in the industry I am more used to dealing with stocking distributors that hobby catalog houses. It is often more important to be able to get parts, than to be able to get the best ones. A design that relies on the best often gets into trouble when the source dries up. Of course that really does not effect hobbyists who are building or upgrading just one or two units.

While there is some crossover to be sure I have found that better supply lines come from stocking distributors (Arrow, Future, Avnet, etc) instead of catalogs (Mouser, Digikey, Jameco, etc).

Dan

 

[bobmcree]

try telling a ferrari owner that he should buy two volkswagens instead

 

[xyster]

It is easier to replace two volkswagons than it is a ferrari. Especially when the ferrari dealership has closed down.
Dan

The Xclyte controllers, with the possible exception of some new models using IRFB4310's, come with unreliable, breakdown-prone Volkswagon MOSFETs. The entire point is to replace the stock 6 or 12 Volks-FETs with 6 or 12 FerrariFETs, greatly lessening the risk of a more expensive controller failure later, while improving efficiency and power capability too. Replacing VolksFETs with VolksFETs makes no sense.

 

[bobmcree]

as xyster pointed out, we are not talking about a new design; i was merely letting my friends know that there was a better price available on this part, which is by far the best drop-in replacement in the controllers most of us use. this was not intended to be a discussion of manufacturing large numbers of parts for a product.

i have worked in the electronics industry for over 30 years, and i have seen the argument presented many times by purchasing agents that they could save the company a fortune if i would only let them substitute this part or that which they have discovered, and seems equivalent to them, and after all they do have advanced degrees (in business, that is)

this is not a newsgroup dedicated to manufacturing cost-conscious products. at least this thread is not. if anyone has found a better deal on the 4110s they are welcome to post it. i have not found anyone who can compete with irtronix for parts they have in stock.

every company i have worked with has used parts from whichever reputable vendor has them in stock or offers a better price among those who have stock. i have watched future / active/ hamilton /avnet etc, grow, split, change names, etc. while digikey and newark remain the same and almost always have stock, sometimes at a bit higher price.

why someone would try to convince members of this forum that they should replace their fets with a product with no better specs rather than the best devices available is beyond me, unless maybe they have stock in the company making the inferior devices or their distributors?

we are trying to extract the best performance from an existing product. we are not designing from scratch. there is no better device for drop in replacement than the 4110. there is no better price on these fets than the one i told my friends about. feel free to use inferior fets in your product and it will probably be fine.

let's just remember that if i switch 40A with .010 ohm fets i will see 16w of power dissipated in the fets, and if i cut the Rds-on in half that will be 0ver 7w of heat i will not generate, but can instead feed to the motor. 7w may not sound like much, but take a 7w nite lite incandescent xmas tree bulb and stick it inside your controller. then watch the temperature....

 

[cadstarsucks]

The Xclyte controllers, with the possible exception of some new models using IRFB4310's, come with unreliable, breakdown-prone Volkswagon MOSFETs. The entire point is to replace the stock 6 or 12 Volks-FETs with 6 or 12 FerrariFETs, greatly lessening the risk of a more expensive controller failure later, while improving efficiency and power capability too. Replacing VolksFETs with VolksFETs makes no sense.

That only holds true if the volkswagon is less than half the ferrari, though I will admit that the tendency is to put in the least they think they can get away with.

If the VW_FET has half the DS resistance with the same thermal resistance it is actually better to replace an F-FET since while the dissipation is the same the ability for the silicon to get rid of the heat is doubled.

Dan

 

[eP]

...
let's just remember that if i switch 40A with .010 ohm fets i will see 16w of power dissipated in the fets, and if i cut the Rds-on in half that will be 0ver 7w of heat i will not generate, but can instead feed to the motor. 7w may not sound like much, but take a 7w nite lite incandescent xmas tree bulb and stick it inside your controller. then watch the temperature....

Hi Bob
You didn't include temperature Rds coefficient factor.
If we assume 25'C degree junction temperature difference (60'C degree Tj @ IRFB4110 and 85'C @ STP) we can calculate much wider heat dissipation difference.
5 mohm (@ 1.3 Tcoeff @60'C ) * 40A *40A = 8W @ IRFB4110
13.5 mohm (@ 1.5 Tcoeff @85'C) *40A *40A =21.6 W @ STP
so the difference is 13.6 W for that case.

The starting assumption (25'C degree difference) is ok. until thermal resistance junction to ambient is greater than 1.85 'C/W.

 

[bobmcree]

as i said "well over 7w". my answer was not meant to be complete, and when we start discussing power dissipation as a more complex concept most members will get lost. thanks for helping others to see that the 4110 is more than twice as good as the original parts, that was my only point.

 

[Jaesin]

I ordered mine from Allied Electronics. They seem to have a very fair price. I paid $2.99 each because I only ordered 12.
http://www.alliedelec.com/search/productdetail.aspx?SKU=2731593

It is annoying to see companies charging over $5 for one of these when they obviously get then for less than $2 each. Allot of these companies really get greedy with the hobbyist.

It is nice to see some companies do have fair prices though. They just want to do good honest business.

< Jaesin >