Toroids and MOSFETs and firmware, oh my! (aka:'Tiny13+N-FET=???')

Helo

I put 70N06 but the performance is very bad (is better then with 35N03 defective)
what can I do? can I change the resistor? what value?
or I can buy 70N02? what about AOD510?

how many amps can I put on 7x T6 in serial?

thank you for help

AOD510 works well, it's not quite as good as the Vishay 70N02 but it's close enough.

Ok…
Now I have 70n06 that has 15mOhm internal resistance…can I put the R13 (10 Ohm) away…or I will burn something?

It depends. You're working with a blue SRK driver, like the one in the first post? Still using the stock MCU or are you using another board with an attiny13 as the controller?

If it works without the gate resistor then it's not needed. If it doesn't, it is.

The board is blue…original just the 35n03 is replaced with 70n06
Do you think that I can remove those resistor?

Why does it need to be removed? Does it work better without the gate resistor? 10 ohm is not enough to have a negative impact on the FET's switching speed, if it works just leave it there and move on to something else that matters.

The problem is that with 70n06 the performance is very very low…how to increse the current to the leds emitors? There are 7 xml t6 conected in series

The drivers in this thread are single cell (3-4.2v) direct drive, as in SkyRay King and the like. I have no idea what driver you have there and what the power source is, if it's able to power 7 LEDs in series.

Helo
I have the same torch as skyray king but the name ultrafire. It has 7 Xml t6 leds in series, driver blue like in the first pages of the forum,

batteries 4x 18650 paralel so 3.7 - 4.2v

When I turned the torch on it stopped working after few minutes. I found FET 35n03 defective so I removed it and put 70n06 ( because I dont have any other at home). Now the light is very low. What to do, to incerease the light power ( the current to the led emitors)

Thank you

Your LEDs are not in series then, they are in parallel. It would take around 23 volts to light up 7 in series, and this is not a boost driver.

Link to the datasheet for your exact FET, please. The same markings used on parts from different manufacturers are not the same, they can have wildly different specs. Make sure you have the right manufacturer, the right part number, and the right revision (if there are any markings on the chip to indicate that).

How did you determine the original FET was defective?

I'm not going to give any specifics for what to check where to diagnose the low output thing until I'm positive we can get on the same page about the actual parts being used here.

Ok…I will open the torch and look for the exact Fet marking
Vith original fet the torch was not working so I connected oscyloscope to the gate and I saw that the imput signal to the fet is OK ( i saw 2 modes, one mode full and one mode 200us ON and 100us OFF - low mode)
Then I changed the fet with the 70n06 and the torch started to work but very low power…

Ok I am going to see the fet marking

If your '70N06' is by Unisonic, the first thing that jumps out at me is that the gate threshold voltage is very very high, compared to the parts known to work well in drivers like this.

On the fet it is writen:
RFP70N06
HO 18
i

This is all

No, that FET is not meant for anything like a low voltage circuit like this, no testing is going to help. Very high gate threshold voltage, very high total gate charge. Replace it with something more suitable.

ok…thank you for help…I will buy AOD510…
what about gate resistor for AOD510? is 10 Ohm ok?

thank you

I have never tried an AOD510 on that driver with the stock MCU. If it works without a gate resistor, it does not need one. If it does not work without one, it does need one. You are the only one who can lay hands on that particular combination of parts, you will have to figure out what it needs.

I like to buy 70N02 but I cant find it anywere.is there another alternative fet?

Alpha & Omega AOD510. http://www.aosmd.com/pdfs/datasheet/AOD510.pdf

I see that all the two fet is dificoult to find it

There should not be any trouble finding the AOD510 somewhere in EU, they are still in production. The Vishay 70N02 is discontinued, that one you are not likely to find in stock anywhere.