design issue

[Gecke Rün]

hi all,

When designing pcb is it preferable the powerfeed is mounted on the pcb? I
need a 2 watt coming from 220 V (220 V AC -> 5V DC). Since I don't want the
pcb to be to large (between 30 and 40 cm˛ I don't need a lot of chip space
though) How big is such a powerfeed . Is it easy to mount it to the pcb and
won't it generate to much noise?

kind regards
Gecke

 

[Rene Tschaggelar]

Gecke Rün wrote:

hi all,

When designing pcb is it preferable the powerfeed is mounted on the pcb? I
need a 2 watt coming from 220 V (220 V AC -> 5V DC). Since I don't want the
pcb to be to large (between 30 and 40 cm˛ I don't need a lot of chip space
though) How big is such a powerfeed . Is it easy to mount it to the pcb and
won't it generate to much noise?

There are safety distances around the holes and pads for the high
voltage. Plus the additional testing required for the high voltage
rules. For few pieces that may not be worth the effort.
The low voltage rules allow a lot that is not allowed for high
voltage. EG the high voltage cable have to be double insulated
and such.

What is the intended lot size ?

Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net

 

[Active8]

On Thu, 13 May 2004 13:07:56 GMT, Gecke Rün wrote:

hi all,

When designing pcb is it preferable the powerfeed is mounted on the pcb?

depends.

I
need a 2 watt

you mean the circuit draws around 10 mA ? How is it that people know
how many watts need to be supplied prior to knowing the current?

coming from 220 V (220 V AC -> 5V DC). Since I don't want the
pcb to be to large (between 30 and 40 cm˛ I don't need a lot of chip space
though) How big is such a powerfeed . Is it easy to mount it to the pcb and

can you solder? Use hand tools? Will it be assembled by carbon based
life forms? Is there other circuitry on the board?

won't it generate to much noise?

no more than's been generated here lately

kind regards
Gecke

This is no doubt a situation where you need an ac/dc converter (wall
wart... power cube... little plastic plug into the wall with wire
and 5 VDC plug thingy...) that delivers 5 VDC from 220 VAC -
available at your favorite electronics department. Then you won't
need the number for emergency services.

A 5 VDC jack on the pcb could be as small as say 1x1x2 cm or you
could have a jack mounted in a chassis hole with wires running to
the PCB and even a little header connector thingy like the ones that
connect the speaker to your computer mobo.

Chances are, the company that manufactures the jack can supply a
mechanical drawing if it's not in the distributor's catalog.

--
Best Regards,
Mike

 

[Gecke Rün]

"Rene Tschaggelar" <none@none.net> wrote in message
news:40a387eb$0$714$5402220f@news.sunrise.ch...
Gecke Rün wrote:

hi all,

When designing pcb is it preferable the powerfeed is mounted on the pcb?
I
need a 2 watt coming from 220 V (220 V AC -> 5V DC). Since I don't want
the
pcb to be to large (between 30 and 40 cm˛ I don't need a lot of chip space
though) How big is such a powerfeed . Is it easy to mount it to the pcb
and
won't it generate to much noise?

There are safety distances around the holes and pads for the high
voltage. Plus the additional testing required for the high voltage
rules. For few pieces that may not be worth the effort.
The low voltage rules allow a lot that is not allowed for high
voltage. EG the high voltage cable have to be double insulated
and such.

What is the intended lot size ?

Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net

Thanks for the answer.

It is actually for a schoolproject and doesn't need to be build in real
life. I have to design a product and was wondering what i do best withg the
powerfeed. The lot size will be very big though (seveal 100 000 ). You
know where I can find specs regarding the safety concerning the high
voltage? Do you have an idea of the size of such a powerfeed?

kind regards
Stijn

 

[Rene Tschaggelar]

Gecke Rün wrote:

"Rene Tschaggelar" <none@none.net> wrote in message
news:40a387eb$0$714$5402220f@news.sunrise.ch...
Gecke Rün wrote:


hi all,

When designing pcb is it preferable the powerfeed is mounted on the pcb?

I

need a 2 watt coming from 220 V (220 V AC -> 5V DC). Since I don't want

the

pcb to be to large (between 30 and 40 cm˛ I don't need a lot of chip space
though) How big is such a powerfeed . Is it easy to mount it to the pcb

and

won't it generate to much noise?


There are safety distances around the holes and pads for the high
voltage. Plus the additional testing required for the high voltage
rules. For few pieces that may not be worth the effort.
The low voltage rules allow a lot that is not allowed for high
voltage. EG the high voltage cable have to be double insulated
and such.

What is the intended lot size ?

Rene

Thanks for the answer.

It is actually for a schoolproject and doesn't need to be build in real
life. I have to design a product and was wondering what i do best withg the
powerfeed. The lot size will be very big though (seveal 100 000 ). You
know where I can find specs regarding the safety concerning the high
voltage? Do you have an idea of the size of such a powerfeed?


Well, 3 pins, Earth, Neutral and Phase with say a distance of 5
or 8mm each. The information should be available at IEC ???.
Not for free usually.

Rene

 

[N. Thornton]

"Gecke Rün" <mepisto@hotmail.com> wrote in message news:<MqKoc.105673$dk7.6307871@phobos.telenet-ops.be>...

hi all,

When designing pcb is it preferable the powerfeed is mounted on the pcb? I
need a 2 watt coming from 220 V (220 V AC -> 5V DC). Since I don't want the
pcb to be to large (between 30 and 40 cm˛ I don't need a lot of chip space
though) How big is such a powerfeed . Is it easy to mount it to the pcb and
won't it generate to much noise?

kind regards
Gecke

Wall wart. Trouble with putting a mini transformer on the PCB is it
puts a lot of stress on PCB when it gets dropped - and on the TF to
PCB joints. Trouble with a SMPSU is it costs more. Wall wart option
means no mains voltage concerns, and regulations there-relevant-to.


Regards, NT