BPA300 Round 2

[rhysh]

wich is the BOM of the DRV134?

1 x DRV134
2 x 0.1uf capacitors
3 x molex kk .156
1 x 3 way terminal block

 

[juluska]

another possible stereo layout

With only one toroidal transformer 1000VA 4x25V.
What are the exact measures of amplifiers pcbs?

 

[rhysh]

4.8"X3.2" INCH

Using one transformer would be fine.

 

[huy5005]

I think you should have current limiter or soft start circuit for 1000VA transformer ? 'cause of the in rush current.

 

[juluska]

I think you should have current limiter or soft start circuit for 1000VA transformer ? 'cause of the in rush current.

Do you Know a simple soft start circuit i can install easily?

 

[huy5005]

Check out the aleph power supply at this link

http://www.penguinlovers.net/audio/aleph2_pswire.jpg

 

[rhysh]

http://sound.westhost.com/project39.htm

 

[rhysh]

Check out the aleph power supply at this link

http://www.penguinlovers.net/audio/aleph2_pswire.jpg

Before anyone asks, we dont use inductors/chokes for this build.

 

[juluska]

SOFT START

What about this ebay soft start circuit, is rated at 10A. The resistor is 47ohms, 20W. Will this be enough?

ebay item: 150322713013

Thanks

 

[juluska]

more photos

 

[tryonziess]

Use a couple of thermistors like Cl60 or whatever matches your particular amp needs. Install a time delay on relay to switch out the thermistors and bring in the line load. A decent timed delay on relay on Ebay is not too terrible expensive and the thermistors are dirt cheap.
ESP audio the Rod Elliot site has a good soft start circuit. Just google and you should not have any problem finding it.

Tad

 

[samsagaz]

1 x DRV134
2 x 0.1uf capacitors
3 x molex kk .156
1 x 3 way terminal block

Can you please poing me to some website where can i see an pic of the "3 way terminal block"?

and i see your website and TI Datasheet where i see that say 1uf instead 0.1uf, this will be the same?

Regards

 

[HaLo6]

So if I use a ~500Va trafo I shouldn't need a soft start circuit correct? i am new at this and am trying to keep this as simple as possible 🙂

 

[rhysh]

Can you please poing me to some website where can i see an pic of the "3 way terminal block"?

and i see your website and TI Datasheet where i see that say 1uf instead 0.1uf, this will be the same?

Regards

Sorry, i was thinking the wrong thing here. 1uf is correct.

I have to hurry off somewhere now, i will post the terminal block when i get back.

 

[rhysh]

So if I use a ~500Va trafo I shouldn't need a soft start circuit correct? i am new at this and am trying to keep this as simple as possible 🙂

Maybe. I would still use some form of soft start with 500va. A lot of people dont keep in mind.

 

[AndrewT]

The mains fuse needed for a transformer or motor is about
transformer power Times three Divided by mains voltage.
Fuse rating = VA * 3 / Vac.
This applies to any size of transformer.

If you are happy using a fuse three times as big as you need then go ahead.
I recommend close rated fusing that allows the amplifier (or any equipment) to run with in it's design specification and does not suffer from nuisance fuse blowing.
This fuse rating <= VA / Vac.

eg.
100VA transformer running on 110Vac.
Without soft start it requires a T3A fuse. Close rated fuse could be between T600mA and T1A
Now try that for 300VA and 500VA and 1kVA.
I know which I prefer.

 

[TS Lo]

Soft start

Hi,

I bought a kit from China for 70.00 Yen(RMB).
1.00 USD = 6.8 Yen

Cheers
TS

 

[TS Lo]

Soft start

Hi,

Schematic diagram.

Cheers
TS

 

[rhysh]

6 more people to pay. Nothing is moving until everyone has paid up. 🙂

 

[beaver]

Payment sent!
Looking forward to build this ampifier.

Thanks rhysh for organizing this groupbuy 🙂