Dual parallel box question

[Evolve82]

Hi guys,
I've built the box in photo

Using IRLB3034PBF but i've few answer because I'm new to box modding:

What is the lowest resistance can I build on this box? I have read a post where the current 'limit' is about 34A, it is correct?

What type of wiring do you use?
Just for testing l've used D2mm copper phosphorus brazing rods, testing the drop there is no too voltage loss, about 100mA with load, but the rod on left heats too much, specially with .1/.15 builds..

Any suggestion?
Thanks !!!



Inviato dal mio SM-G925F utilizzando Tapatalk

 

[david4500]

Without a heatsink and observing thermal limitations of the mosfet, it's about 30 amps. The heatsink you are using, are there specifications for it which list the amount of power it can dissipate?

This videos goes into figuring power dissipation and thermal limitations

 

[Evolve82]

Thanks David, i'll check the heatsink datasheet, very useful video.
Talking about wiring problem/heating, what do you think about?

Bye

 

[WharfRat1976]

Your Fet is bad is one possibility.

A .1 build is drawing 40 amps at 4volts. Too much draw for a parallel circuit.

The box is parallel, correct?

.15 ohms will draw 26.66 amps
.2ohms will draw 20 amps
.3 ohms will draw 13 amps

Your wire is around 12 guage which is great but using phosphorous rod maybe the problem as well.

Usually, builders use regular wire either single strand or multi cores and they are bendable around the corners so they do not have to solder the elbows.

Those solder spots maybe a problem as well.

Are your batteries getting hot or just the left rod?

 

[edyle]

Hi guys,
I've built the box in photo

Using IRLB3034PBF but i've few answer because I'm new to box modding:

What is the lowest resistance can I build on this box? I have read a post where the current 'limit' is about 34A, it is correct?

What type of wiring do you use?
Just for testing l've used D2mm copper phosphorus brazing rods, testing the drop there is no too voltage loss, about 100mA with load, but the rod on left heats too much, specially with .1/.15 builds..

Any suggestion?
Thanks !!!



Inviato dal mio SM-G925F utilizzando Tapatalk

The long rod on the left is unnecessary.
It should be short and connect to a much closer point on the metal body of the box.

 

[Evolve82]

Your Fet is bad is one possibility.

A .1 build is drawing 40 amps at 4volts. Too much draw for a parallel circuit.

The box is parallel, correct?

.15 ohms will draw 26.66 amps
.2ohms will draw 20 amps
.3 ohms will draw 13 amps

Your wire is around 12 guage which is great but using phosphorous rod maybe the problem as well.

Usually, builders use regular wire either single strand or multi cores and they are bendable around the corners so they do not have to solder the elbows.

Those solder spots maybe a problem as well.

Are your batteries getting hot or just the left rod?

Only the rod, thanks for the answer

 

[Evolve82]

The long rod on the left is unnecessary.
It should be short and connect to a much closer point on the metal body of the box.

If i connect the negative pos of the battery to the box it fires!

 

[Tom Waznis]

Hi guys,
I've built the box in photo

Using IRLB3034PBF but i've few answer because I'm new to box modding:

What is the lowest resistance can I build on this box? I have read a post where the current 'limit' is about 34A, it is correct?

What type of wiring do you use?
Just for testing l've used D2mm copper phosphorus brazing rods, testing the drop there is no too voltage loss, about 100mA with load, but the rod on left heats too much, specially with .1/.15 builds..

Any suggestion?
Thanks !!!



Inviato dal mio SM-G925F utilizzando Tapatalk

Yea. Don't stand close to me when you fire it.