PSU...??

[mattias]

Wouldn´t this be good for MBFM?

It´s like 20 euro from ELFA.. Maybe Ishould get one for my SID also?

What about fuses, were do i put them?

[seppoman]

Hi,

looks nice. What are the voltages of S1..S3?

If you want a ready to use PSU, take a look at pollin.de - they have a +5/+12/-12V regulated PSU with mini-DIN connector (like PS/2) for only 3.95 Euros:

http://www.pollin.de/shop/shop.php?cf=detail.php&pg=OA==&a=MDU0OTQ2OTk=&w=Njk1OTc5&ts=0

They ship internationally - don´t know the postage though...

Seppoman

[mattias]

Can´t say.. I am not an electronics expert. I think 8.5 V s1 and 14 V s2 and s3!! But here is the data from elfa.

Mfr. Noratel (former Toroid

Toroidal core transformer adapted to produce 5 and ±12 V regulated direct voltage. Designed to provide sufficient voltage down to 10% for low mains voltage. Primary voltage 230 V, centre tap for 115 V. Fusing is best performed on the secondary side with a fuse value as close as possible to the winding's rated current. Simple installation with a single centre bolt.

  Primary voltage: 0 (black)-115 (white)-230 V (yellow)

  Secondary voltage: 8.5 V (white-black)+2×14 V (green-red, brown-blue)

  Certificates: UL

  Manufacturing standard: EN61558

  Connection: Cable, 200 mm

  Output Voltage Dim Weight

  Type VA Vac mm kg

  AA-18120-TI 55 (25 + 2×15) 8.5 + 2×14.4 Æ82×h35 0.7

  AA-18420-TI 120 (70 + 2×25) 8.5 + 2×14.1 Æ93×h47 1.2

  Max IDC Max IDC Rec. cap. Rec. cap.

  5 V output 12 V output C1 C2, C3

  Type A d.c. A d.c. ?F ?F

  AA-18120-TI 2.0 0.8 15000 2200

  AA-18420-TI 4.5 1.0 22000 4700

There is 2 kinds as you can see. But anyhow your alternative looks very interessting since it´s totaly plug and play.

../Mattias

[seppoman]

Hi,

8.5 and 14 V is perfect. If you go that way, just take the cheaper variant, it still is way stronger than necessary.

Seppoman

[AndrewMartens]

Wow, toroidal transformer and everything.  Very nice!

I'm probably going to make do with a crusty old 24V transformer I looted from a spare parts / junk box at my old company...

[b-funk]

that´s exactly what i´m looking for...

any hints where to get this one in germany? ordering it directly from elfa is too expensive - they demand 45 € for delivery to germany  :o

[Echopraxia]

Hey doors did you end up going with this power supply that you were thinking about? How did it fair? Would you buy it again for next mbfm? What is the model number?

[warland]

Toroidal transformers are always the best choice over other transformer designs.

In simple terms they are more efficient and due to the "closed" magnetic aspects

of their construction are less prone to produce EMF type noise.

As to fusing, remember a fuse or circuit breaker is intended to protect what comes

after it in the circuit, NOT what comes before it. In this schematic a fuse of no more

than the primary winding's rated current should be fitted. In this case I would fit a

500mA fast blow in the "live" wire of the primary. This particular tranny appears to

have a tapped primary for connection to 2 different supply voltages. (probably 110

or 220-240). Never fit a fuse in the return or neutral side of the primary as if this

blows and the device is still connected to the AC supply, a lethal voltage is still present

on the tranny.

The secondaries should be protected by a 1 Amp slow blow on each secondary. In this

case one in connected between the white wire and the bridge rectifier and one connected

between the green wire and it's bridge rectifier should be sufficient.