Making car amplifier SMPS with tl494 + DC Protection

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#181
Re: TL494 smps.

gearheaddruid said:

I made one amp using two ETD59 cores for power supply. I wound the primary with copper foil insulated by teflon sheet. The secondary was heavy litz wire taken from an old ultrasonic cleaner supply. The amp ended up with 900 watts RMS per channel into 4 ohms. I have learned a lot the hard way! Litz wire is the only way to go, it gets rid of the "skin effect" and makes the supply more efficient. I recently bought out a transformer winding company's inventory and have a lot of litz wire in my warehouse. I will be offering it for sale as soon as I get it all cataloged.
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Steve -- how did you strip the litz wire?
jack
 
#182
Litz wire explained.

Thanks for the response all! Litz wire was designed to get around what is called the "skin effect" of wire. At higher frequencies the electrons only travel on the surface of the wire. This greatly reduces the effective current carrying ability of a solid wire. One way to avoid this loss is to use copper foil for windings. Not easy for us average joes to work with.
Litz wire is just a lot of verry small wire braided together to make a large conductor. This gives a lot of skin area within the conductor. The wire I used was enameled insulation. To remove the enamel for soldering on the ends you can use a chemical stripper or just heat it up with a solder gun to burn the enamel off. I then used a good flux with solder and made a terminated end.
You can find litz in old d.c. to d.c. converters, some p.c. supplies, ultrasonic cleaners, and a lot of old industrial power supplies.
Hope this clarifies the idea. Regards, Steve
 
#185
Stripping Litz wire.

There is a product called Strip-EX sold through electronic parts stores. It is kind of messy and needs a lot of ventilation. I prefer just using a hot soldering gun or small torch to burn the enamel. scrape off the burnt stuff, a little flux and solder will give you a nice termination. Regards, Steve
 
#186
Not identify this chemical

Hey,
I have a chemical for removing insulation of copper wire but i can not identify that so i cant putdown the name of it and this is not harmfull. I have tryout that and also so chip price about 200.00 indian rupees about 4.00 US$ per litre
 
#189
this is my SMPS and AMP from risto80
 

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#191
Grucho said:
Hi.

I dont have time to draw schematics, but here are my pbc, bottom + top(component) + bottom&componentlayer.

I havent tested thiss fully. So I dont suggest you to build it as final solution . Most of shematics is from valveaudio with minor modifications .
All inductors are about 100uH. (4 inductors)

Mosfets : irfz44N (buz11 also worked).
Gate resistors are 4.6 ohm (vertical)
External wires are drawn with red and green color.

In this smps I used EE core from PC power supply. ETD49 cores will wait for final solution 🙂

Like I said when I find time (this week or week after), I'll do full test with scope .

Bye
Click to expand...


smps11-pcb.zip Thanks Grucho
where schema?
 
#196
Power supply

Hello,
I have a high powered class D amp I would like to power by 12v auto battery(s), if possible? Right now it uses +/- 87vdc and requires 11A @8ohm and 21A @4ohm.This gives over 350w / 600w + respectivley.I could easily live with a lot less output.I would like to use about 65v, but could go as low as 50v.Can anyone help me source or build a supply(s)?
Gary
 
#198
gev

that much of sec is for around +/- 25V unregulated.
use for pri 5 and for sec 18 to 20.

Garytr
Yes it is possible to use smps in car even for +/-85 if you like, but the current drawn from 12v at full power will be high!
is it possible to see your d-amp,some pictures, schemat., PCB?
 
#199
SPMS

gev said:
An externally hosted image should be here but it was not working when we last tested it.

problem low volt ?
Click to expand...

Hey Gev,
Pherhaps I can help you. I have many of projects including SMPS from 230V AC to 80V DC and also several car amps and SMPS'. I think you like this one http://www.diyaudio.com/forums/showthread.php?threadid=67733.

If you are not far, may be we can meet and can solve your problem with your power supply. See my location.

I wrote English because the others can understand what I mean.
Regards.
 
#200
hello everybody

i am in need of all the help i can get

my first SMPS project though it works

the problem was the torroid heats up quickly and i mean HOT

the PWM controller use was TL494CN

plus the fact that the other mosfet is cool while the other one syncronize with the torroid heating up

what seems to be the critical problem of the said project

ANYONE? Plzzzzzzzzz help:bawling: :bawling: :bawling:
 
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