Better undesrstanding of MOSFETS
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https://www.fasttech.com/products/0/...mod-vw-modules
This looks sexy
Def going to have to consider this 1
Another question about mosfets/resistors. Got my box built (2 Efest 20A - Parallel) and would like to use the smaller switch/mosfet in this build. Looked at the diagram and see that the mos needs a 15k 1/4 watt resistor. I have alot of resistors since radio shack went out of business (it was a feeding frenzy However, I do not have a single 15k 1/4 watt resistor. I do have plenty of 10k 1/4w as well as 4.7k 1/4w. Is 14.7k 1/4w close enough using these 2 resistors? (parallel) Want to use a 3 amp switch.
However, I do not have a single 15k 1/4 watt resistor. I do have plenty of 10k 1/4w as well as 4.7k 1/4w. Is 14.7k 1/4w close enough using these 2 resistors? (parallel) Want to use a 3 amp switch.
The resistor is just driving the gate into saturation, so 14.7K or just a 10K should work fine. Just don't go above 15K or you risk running the MOSFET into the linear mode where it will dissipate large amounts of power.
So my mosfets came in and I'm having a problem. It will not fire any rda (all rda's fire on another device) Put the mosfet box on my multimeter and ohm reader (which has a voltage reader as well) and when I press the switch I am getting 4.2 volts. Tried multiple rda's, tried different coils with different resistances and nothing. Mosfet is not getting hot. Not sure what the problem is
I can't tell 100% from the photos but IF I am seeing a "+" in the battery sled on the left side and IF you are using an nfet such as the normally used IRLB3034 then you have the battery polarity wrong. The source goes to the negative side of the sled, the drain goes to the negative side (outside case) of the 510, the gate goes through the momentary switch to the positive side of the sled, and the center pin of the 510 goes to the positive side of the sled.
1st, I really appreciate the help. Sorry about the horrendous pics (its the only cam I have) Left side of sled is negative, right is positive. Mosfet (IRLB3034) is flipped over (heatsink side up) in pics. I held down the switch to see if the mosfet would get warm (not hot) and it did, so its receiving power. It's just not letting any real power through and I'm not sure why as it is reading 4.2V at the 510.
Best I can tell then you have it wired correctly. David brings up a good point. Ebay fets are notorious for being counterfeit POS, if indeed that is where it came from.
Was pretty sure it was wired correctly, just hoping I overlooked something that some1 would catch (wishful thinking
. I did get these mosfets from ebay (although the seller has a really good reputation) At the same time, after wiring up 4 of them and getting the same results I ordered some from digikey yesterday (they should be here by Monday if I'm lucky) Hopefully I will have better results. Once again, I really appreciate every1's help on this matter and will post back when I get the new mosfets.
Mosfets came in today from Digikey, mission accomplished 
I'll make the wiring a lil prettier, change the fire switch (the contacts broke on the 1 I was going to use) and add a voltmeter as well. Much appreciated to every1 for their help/information.
I'll make the wiring a lil prettier, change the fire switch (the contacts broke on the 1 I was going to use) and add a voltmeter as well. Much appreciated to every1 for their help/information.
well not entirely true.. you can use a PWM circuit. this turns the mosfet on and off at variable time and allows you to reduce voltage also with a pot
https://oshpark.com/shared_projects/D9LvB9km board used
pics of my box
http://i.imgur.com/v7NEdTP.jpg
i get all the power of a series but with the voltage regulation of a raptor etc
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