Spare parts (help needed)

[raid2506]

That's cool testdruif, so 7A min is the constant current of the battery not the input current of the circuit.

Still, the rest of it is dangerous, you cannot make your own home made 2 cell Li-po and charge it from USB, that's called a time bomb.

[testdruif]

Whilest driving home in the car I was thinking some more.

The only reason (I recon) to use a fuse is if one of the wires going from the battery (before the board) completes a circuit.

I need an electronics/electrician expert for this part
In my views the dna20 board is nothing more than a step-up/boost converter always taking in the voltage of the battery (wether it is fully charged or almost empty) and then storing it/boosting it to the required output voltage.

It does not allow you to interact with the battery and coil directly, it's the middleman only allowing you to go to 20 watts (so no voltage you can make).
hence it will never draw more than the battery itself can give. so there would be no need to have a fuse in between the battery and the board itself as the board will never draw more than what the battery has to offer?

If you would not use a board and you put together a pure mechanical mod it may be wise to use a fuse because with a freshly charged battery at 4.3 volts discharge and a coil of 0.5 ohm that would be 37 watts and 8.6 amps which would be a little dangerous.. and it only goes up when you apply a lower ohm coil.

[Super-Shiny]

raid2506 testdruif just made this diagram, does this look ok?

[testdruif]

Jan 6, 2014 17:37:07 GMT Super-Shiny said:

raid2506 testdruif just made this diagram, does this look ok?

yes the same as 30 posts ago but now more confirmed than back then

[testdruif]

when that mod of yours comes together I'm going to be livid!

I have my current one which I like very much but as it was a test box for my equipment I had it's far from beautiful. (it's more practical ^^)

So when you have yours put together I'm going to pick your brain!!!! and if possible use you as a mule to traffic some parts (the box and battery holder) from the UK to Belgium

Looking forward to hearing/reading your experiences with building and the finished product

[Super-Shiny]

Jan 6, 2014 17:38:35 GMT testdruif said:

yes the same as 30 posts ago but now more confirmed than back then

I only made it as when i draw things it sinks into my brain better for when i make it

Forgot to add i don't think the DNA20D can take sub ohm coils, they mention it on Breaktru.....just aswell all my coils are 2ohms.

[testdruif]

yeah, mine sometimes goes from 1.2 to 1.1 and then the ohm reading starts flashing and it pumps out the lowest it can which is 3.4
I haven't tried yet with something below 1.0 though to see if it stops doing anything.

[raid2506]

Jan 6, 2014 17:37:07 GMT Super-Shiny said:

raid2506 testdruif just made this diagram, does this look ok?

It seems sound to me although I would be inclined to use a single 6A fuse.

[testdruif]

Jan 6, 2014 18:07:11 GMT raid2506 said:

Jan 6, 2014 17:37:07 GMT Super-Shiny said:

raid2506 testdruif just made this diagram, does this look ok?

It seems sound to me although I would be inclined to use a single 6A fuse.

and if you would go looking for 1 x 6 amps fuse you might as well pick up a 7 amps fuse instead. So you can use the board to its fullest?

[Super-Shiny]

I looked for a fuse on RS but all that trip time and cut off times confused me, this is what i have: uk.rs-online.com/web/p/resettable-wire-ended-fuses/5176821/

Click on similar products tab underneath and see if you can direct me to one

p.s Updated the diagram a bit to include USB charger

[testdruif]

Jan 6, 2014 18:34:13 GMT Super-Shiny said:

I looked for a fuse on RS but all that trip time and cut off times confused me, this is what i have: uk.rs-online.com/web/p/resettable-wire-ended-fuses/5176821/

Click on similar products tab underneath and see if you can direct me to one

p.s Updated the diagram a bit to include USB charger

I would maybe go for this one

uk.rs-online.com/web/p/resettable-wire-ended-fuses/5176916/

Safely operates at "Hold Current 4A"
Trips at "Trip Current 6.8A"
Trip time "Time to Trip 1.7s" (amount of time it takes for the fuse to trip/figure out it needs to trip)

The datasheet for the DNA20 mentions "typical input current at 4amps"

But we need a fuse expert for this! as I'm not sure. if you solder everything up and it turns out it's not working

[Super-Shiny]

testdruif out of 1 too 10 what score would you give that fuse to be the correct one? i don't mind getting it but their postage costs are

[testdruif]

Jan 6, 2014 18:50:13 GMT Super-Shiny said:

testdruif out of 1 too 10 what score would you give that fuse to be the correct one? i don't mind getting it but their postage costs are

I would give it a ? as I have never worked with those kinds or fuses in my life

[testdruif]

Jan 6, 2014 18:51:52 GMT testdruif said:

Jan 6, 2014 18:50:13 GMT Super-Shiny said:

testdruif out of 1 too 10 what score would you give that fuse to be the correct one? i don't mind getting it but their postage costs are

I would give it a ? as I have never worked with those kinds or fuses in my life

I've read up on it.

PCB Wire Ended
Resettable fuses with radial leads that offer the following:
All are UL, CSA, TUV approved
Protection of electrical and electronic circuits against excessive currents
Rapid switch from low resistance state to very high resistance with electrical overload or short circuit
Quick and automatic reset and return to low resistance state when fault condition corrected and power removed

So correct me if I'm wrong, the way these fuses work is increasing their resistance when it exceeds the amount of amps going through it
Which would make it heat up (apparently it's intended use). This may or may not cause damage in the housing to your wires and electrics etc...

It says returns to low resistance state when fault condition corrected and power removed

Sooo will you be able to get your mod open fast enough and get your battery out before the thing melts?

[Super-Shiny]

Jan 6, 2014 18:51:52 GMT testdruif said:

Jan 6, 2014 18:50:13 GMT Super-Shiny said:

testdruif out of 1 too 10 what score would you give that fuse to be the correct one? i don't mind getting it but their postage costs are

I would give it a ? as I have never worked with those kinds or fuses in my life

I will wait until tomorrow and see if raid2506 might be able to shed some light, i won't be starting to build it until the weekend anyway as i am waiting for some more bits, best news is my 3mm Dark blue tint acrylic sheet polished and cut to size has finally been dispatched