Novak T4

[urban hype]

Hello All, In one of my recent car purchases I got a Novak T4. It is still functional but it seems that the brake mosfet is blown in it. Does anyone remember if the drive mosfet are the same as the brake mosfet? Does anyone remember who made the mosfets? 1 Have 2 other scrap novaks. One is a T1X and the other I believe to be a T1 but possibly may be another T4. They are apart but in the old days they used to sand the serial number off for what ever reason so I may have mosfets to repair it but I would rather know that they are correct before I go and strip the unit.

[urban hype]

For anyone that is interested I was able to fix my brake fet on my T4 with another part. You can use a RFP70N03. It has a similar spec to the original. I have installed it on my speed control and it seems to work.

[uniquenamehere]

Nice... thank you for the info. I have an old T4 from back in the day...

Where did you get the replacement part?

[UserUnrelated]

I too have a T-4, and I don't think the brakes work... I'm not 100% sure yet though, I haven't driven the truck anywhere but my room (it's snowy outside!)
If it ends up being blown, I'll try the part you mentioned and report back.

EDIT: if I can even find it...

[urban hype]

The part number is a current production part. I got it at Sayls in Toronto. If you don's have access to a good electronic store I am sure you can find the part at Digi-Key. The spec is:


Original - 50A 50V 0.022 Ω N Channel Power Mosfet - RFP50N05

Substitute - 70A 30V 0.022 Ω N Channel Power Mosfet - RFP70N03

It seems that there are 2 manufactures Intersil and Harvey. Harvey is the original

Also if anyone has an open T1 / T4 I would like to know the number of the drive fet so I can try to get a replacement for that also.

As a side note I remember that it was a rather common problem with the T1/T4 series that the brake fet would blow. The problem is that they sanded off the the number so that we could not get a replacement.

[uniquenamehere]

Oh awesome, didn't realize you were in Toronto. I'm in Waterloo, (home of BlackBerry!) and we have a Sayal in town...or used to, I'll check.

Come to think of it, I never remember much braking power with my T4 even when it was new. I wonder if it's blown...

[urban hype]

Yea I am from Toronto. I just checked there is no Sayal in Waterloo but there is one in Cambridge. It is a lot closer than the other stores. Much to my misfortune all of the good electronic component store are almost extinct.

To make the T4 have better brakes you have to spend some time fiddling with the pots. There is a sweet spot. But I do agree it did not have the greatest brakes. If you take out the brake fet and see the number for the drive fet please do me a favor and post it. I want to know if they are the same.