my LM3886 Amply fire

[jamal]

my LM3886 Amply fire

[CLS]

Nice

I hope you don't use WBT type of RCA plug or speaker cable with spade type lugs. The connectors on your chassis might probably turn with the force you apply to them.

And, what are those 5W resistors for?

[jamal]

those 5W resistor are from Calos Filip power supply circuit. Actually I can't find a low wattage low ohms resistor. low reistance resistor is available in 5W here.

[imfree707]

Nice construction job and design. The amp should produce a delicious, fresh,clear, Sterelite Food Container crisp sound! A little unconventional in choice of cabinet, but conservatively designed, and should be reliable. Interesting!

[AndrewT]

Hi,
do you have all the exposed metal parts connected to Safety Earth?
Is your Safety Earth connected to the PE of the power socket?

[pacificblue]

It is a no-go to connect a green/yellow wire to the fuse holder and use it as power lead. Green/yellow is reserved for PE.

[jamal]

hey, Thanks. I just added 5 LED tri color . each LED will turn from red to blue then green. then it will blink blink blink and whole process start again by itself without additional circuit. all is build in to LED.
some one thought the plastic box is on fire, until I told them it is not.

AndrewT, yup those connection are connected to earth. infact the connection have been change drastically to include star topology .the current photo is not taken yet.

Originally Posted by imfree707

Nice construction job and design. The amp should produce a delicious, fresh,clear, Sterelite Food Container crisp sound! A little unconventional in choice of cabinet, but conservatively designed, and should be reliable. Interesting!

[jamal]

oh dear, I forget to include a fuse. an amplifier inside a hazardous casing with out a fuse.
brothers, wat is the math for the fuse ,for the primary and secondary winding.

Originally Posted by pacificblue

It is a no-go to connect a green/yellow wire to the fuse holder and use it as power lead. Green/yellow is reserved for PE.

[AndrewT]

Hi,
the primary fuse can be rated as 3 * VA / supply voltage.
This results in a big fuse value that does not suffer nuisance blowing at start up but needs an enormous fault current to pass to make it rupture. I don't like this, there is a risk of severe overheating in the faulty apparatus before the fuse eventually blows.
I prefer to close rate the fuse (Fuse rating <= VA / supply voltage), but this requires the use of a soft start to prevent nuisance blowing at start up.

The secondary fuses (one in each supply rail after the smoothing caps) can be rated as 0.5 * sqrt[ Output Power / speaker Ohms]

Use F (fast) rated fuses in the secondaries and use T (time delayed) rated fuse in the primary.

[jamal]

but I dont like to use fuse you see I am using heavy gauge wires to accomplish low resistance for high current flow, then if I put a thinly fuse wire will it effect the current flow if not then wire people use heavy gauge to power large load......thanks