Hi risto
I do not have any ready designs for sub woofer but have software. let me know your speaker parameters, and i can post the box for it.
Also I built your SMPS, very good will run without heatsinks on the mosfets without load, no heat until load.
I am using mosfets IRFZ48N /0.018ohms 50 AMPS. But the capacitance on the gate is high. can I replace the 100ohm resistors with something smaller like 47 ohms or even less??
Thanks
I do not have any ready designs for sub woofer but have software. let me know your speaker parameters, and i can post the box for it.
Also I built your SMPS, very good will run without heatsinks on the mosfets without load, no heat until load.
I am using mosfets IRFZ48N /0.018ohms 50 AMPS. But the capacitance on the gate is high. can I replace the 100ohm resistors with something smaller like 47 ohms or even less??
Thanks
Hello
I plan to by USBLASTER speacker 12 inch. its only 35 euro.
The only things I know about this subwoofer is from the usblaster site the name for this sub. is usb-2932.Specifications are:
Size 30 cm
Dual voice coil sub
Max. Input power 2000 W
Rated Input power 400 W
Sensitivity 90 dB
Frequency response 22 Hz-1 Khz
Impedance 2x4ohm
With Inductance loop
Edge Rubber surround
Cone Injection
Magnet 50 Oz
Please sorry for my bad english but I dont know what is capacitance?
I plan to by USBLASTER speacker 12 inch. its only 35 euro.
The only things I know about this subwoofer is from the usblaster site the name for this sub. is usb-2932.Specifications are:
Size 30 cm
Dual voice coil sub
Max. Input power 2000 W
Rated Input power 400 W
Sensitivity 90 dB
Frequency response 22 Hz-1 Khz
Impedance 2x4ohm
With Inductance loop
Edge Rubber surround
Cone Injection
Magnet 50 Oz
Please sorry for my bad english but I dont know what is capacitance?
Spiro, I use a similar design with 4 IRFZ20's driven directly from a SG3525 and use 47 ohm gate resistors and it works great.
Risto, Capacitance is the property of an electric conductor that characterizes its ability to store an electric charge. So using a lower value resistor can increase switching efficiency by decreasing the effect that gate lead capacitance has on switching times.
Risto, Capacitance is the property of an electric conductor that characterizes its ability to store an electric charge. So using a lower value resistor can increase switching efficiency by decreasing the effect that gate lead capacitance has on switching times.
How to build Feritte toroid 4 SMPS with tl494+DC protection
there is a feritte toroid in SMP Sschematic . I did not know hou to making this Feritte toroid core . I want to build SMPS for 300w-400w car amp.
I have some unused PC power supply (230v 235w 4A) and i see some(3) core there (see attach pic). my question is
is this feritte toroid ?
and may i use this feritte toroid in SMPS without modefication?
There is 3 feritte toroid and which one i can sued? (biggest one?)
Any one suggest plese.
Regards
Robin
there is a feritte toroid in SMP Sschematic . I did not know hou to making this Feritte toroid core . I want to build SMPS for 300w-400w car amp.
I have some unused PC power supply (230v 235w 4A) and i see some(3) core there (see attach pic). my question is
is this feritte toroid ?
and may i use this feritte toroid in SMPS without modefication?
There is 3 feritte toroid and which one i can sued? (biggest one?)
Any one suggest plese.
Regards
Robin
Attachments
the cores are too small for a SMPS. even the biggest one is still too small. you need a core of atleast 1.5" in diameter for a 200 watt PSU.
and also, the cores are powdered iron. you need ferrite. the toroids you mentioned can be used as input filtering so that your amp SMPS will not put spikes or noise into the car electrical system.
and also, the cores are powdered iron. you need ferrite. the toroids you mentioned can be used as input filtering so that your amp SMPS will not put spikes or noise into the car electrical system.
Hey risto
This is really good,the sharing of the design of SMPS
Your 12" subwoofer, you require t/s specifications. Without those, the box can only be guessed. heres a link
http://www.diysubwoofers.org/sbc/sbc2.htm
regarding SMPS
Only problems are
-I can make single sided PCB right here at tech in a DIY fashion,but unsure about double sided.
-is the kac-716 amplifier PCB single sided ? i only see one side.
2 of my friends are looking for car amplifiers such as this,for small subwoofers.This maybe very useful!
Cheers!
mike.e
This is really good,the sharing of the design of SMPS
Your 12" subwoofer, you require t/s specifications. Without those, the box can only be guessed. heres a link
http://www.diysubwoofers.org/sbc/sbc2.htm
regarding SMPS
Only problems are
-I can make single sided PCB right here at tech in a DIY fashion,but unsure about double sided.
-is the kac-716 amplifier PCB single sided ? i only see one side.
2 of my friends are looking for car amplifiers such as this,for small subwoofers.This maybe very useful!
Cheers!
mike.e
Hi risto, I looked at the subwoofer you mentioned earlier and could not find enough specs for making the box. even on the manufacturers web site.
Mainly I would like to contribute some improvements for any one making or has made a SMPS for car amplifier.
1) if you are getting the following symptoms:-
a. large spikes on the fets
b. too much current draw when the SMPS is idle
c. the transformer getting warm at even low power levels.
then try this: add a few more windings. this will reduce the amount of magnetic flux in the core, this will prevent saturating core (heating), reduce the voltage spikes and improve efficiency.
2) if you are not getting enough power. (i get over 300W with my small ferrite core.) Then you need to use thicker wire/ better still parrallel several wires together. I re wound my core several times using thicker and thicker windings every time, until I could not physically fit any more wire through the hole.
Something to concider is that the Magnetic flux in the core is the same from 1amp to 1000 amps. it's the voltage per turn and the frequency that will determine the flux saturation limit. so as far as current goes the only limitation is the wire thickness and the mosfet on resistance.
I have used 8 turns per primary, and 22 turns per secondary.
Each primary is 5 x 1mm thick wire
Each secondary is 2 x 1mm thick wire
the core I used is MATERIAL L15 SIZE 35mm X 21mm X 13mm
Frequency is about 38Khz
Mainly I would like to contribute some improvements for any one making or has made a SMPS for car amplifier.
1) if you are getting the following symptoms:-
a. large spikes on the fets
b. too much current draw when the SMPS is idle
c. the transformer getting warm at even low power levels.
then try this: add a few more windings. this will reduce the amount of magnetic flux in the core, this will prevent saturating core (heating), reduce the voltage spikes and improve efficiency.
2) if you are not getting enough power. (i get over 300W with my small ferrite core.) Then you need to use thicker wire/ better still parrallel several wires together. I re wound my core several times using thicker and thicker windings every time, until I could not physically fit any more wire through the hole.
Something to concider is that the Magnetic flux in the core is the same from 1amp to 1000 amps. it's the voltage per turn and the frequency that will determine the flux saturation limit. so as far as current goes the only limitation is the wire thickness and the mosfet on resistance.
I have used 8 turns per primary, and 22 turns per secondary.
Each primary is 5 x 1mm thick wire
Each secondary is 2 x 1mm thick wire
the core I used is MATERIAL L15 SIZE 35mm X 21mm X 13mm
Frequency is about 38Khz
USB 2932 T/S parameters
Hi guys !
I also plan to use USB 2932 driver, and after hopeless search for any data I mailed US Blaster. They replied to me within few hours with complete datasheet of the Power Bass (DVC) series. You can see it my attachment.
But I think they made a mistake in some parameters. I think the VAS should be 10 times what is written in the datasheet.
And I don't understand why Voice coil is 50mm long when mechanical Xmax is only 8,5mm. If voice coil is really that long, how can sensitivity be that high (90 dB) ?
I have few ferrite cores at home and would like to make car amp SMPS. The cores are 2cm high with 4cm outer diameter and 2cm inner diameter. How much power do you think I could get from each of those ?
Hi guys !
I also plan to use USB 2932 driver, and after hopeless search for any data I mailed US Blaster. They replied to me within few hours with complete datasheet of the Power Bass (DVC) series. You can see it my attachment.
But I think they made a mistake in some parameters. I think the VAS should be 10 times what is written in the datasheet.
And I don't understand why Voice coil is 50mm long when mechanical Xmax is only 8,5mm. If voice coil is really that long, how can sensitivity be that high (90 dB) ?
I have few ferrite cores at home and would like to make car amp SMPS. The cores are 2cm high with 4cm outer diameter and 2cm inner diameter. How much power do you think I could get from each of those ?
cro maniac-
The efficiency is average. the VC could be overhung.
the vas of 11litres seems rather odd. Perhaps 30litres is possible.
Normally 100litre for many 12" woofers. Note that the reccomended box is extremely small also.
Ask the manufacturer to be sure.
Note that a ported box of less than ~50litres,it will be annoying to tune near 30hz due to excessive port length.
Cheers!
The efficiency is average. the VC could be overhung.
the vas of 11litres seems rather odd. Perhaps 30litres is possible.
Normally 100litre for many 12" woofers. Note that the reccomended box is extremely small also.
Ask the manufacturer to be sure.
Note that a ported box of less than ~50litres,it will be annoying to tune near 30hz due to excessive port length.
Cheers!
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