toroidal wiring

[harps]

hi

I have a toroidal that i hope to connect mains 230v  and have dual 18v as the output.

The physical colour of the wires is visually clear and distinguishable poking out of the toroidal. 

on the sticker it states

Primary 0-115v 0-115v  (blu.gry.pul.brn)   
&
secondary 0-18v (org yel)
0-18v  (blk.red)

am i right in thnking this below is correct.

on the primary for 230v :

solder grey and purple together.
connect mains + to brown
connect mains -  to blue

on the secondary:

solder orange and black together for ground
connect red and yellow to the full bridge rectifier.


Thanks for help and/or confirmation : )

[Gyro]

Yes, that looks correct (not being able to see the label, but from your description its markings are logical and clear).

It's always good to be cautious though. Make sure you have a reasonable rating fuse included on the primary side [Edit: or series mains filament lamp, for the first power-up]

[harps]

Thank you very much Gyro !!

[Cerebus]

From the colour codes that sounds like a Vigortronix toroidal transformer. If it is, then yes, that is correct; I have one here (50VA 2 x 0-25V) that has been powered up and has behaved itself that has been wired exactly like that on the mains side.

However, you had best check the phasing very carefully on the secondary side, as what you are suggesting sounds like wiring the secondaries in anti-phase, which is most probably not what you want.

[basinstreetdesign]

Check the phasing of the primaries, too.  If its wrong then you will have a fairly deadly short on the mains and could damage the transformer.  If you have access to a low ac voltage, such as 12 Vac, then do this by connecting the two primaries, in series to that ac source and then check the voltage found on one of the secondaries.  If it is as expected at Vpri x 230/18 it's good.  If it's very low its wrong.  Just swap the leads on one of the primaries.

You could also use a dim-bulb tester on the primary side if you have one.

[IanB]

Yes, definitely check the phasing of the primaries before connecting to the mains. The consequences of getting that wrong will be quite severe.

[IanB]

on the sticker it states

Primary 0-115v 0-115v  (blu.gry.pul.brn)   
&
secondary 0-18v (org yel)
0-18v  (blk.red)

am i right in thnking this below is correct.

on the primary for 230v :

solder grey and purple together.
connect mains + to brown
connect mains -  to blue

on the secondary:

solder orange and black together for ground
connect red and yellow to the full bridge rectifier.

Remember mains doesn't have "+" and "-" as it's AC.

Similarly the secondary side doesn't have a ground, it is AC also.

It seems that if you connect orange and black together, and then connect yellow and red together, you will have 18 V AC at the full rating of the transformer. But do check the phasing to make sure before you do that.