Re: Clean water = low immunity = more disease

Charles Francis <charles@xxxxxxxxxxxxxxxx> writes
>Thus spake Oz <Oz@xxxxxxxxxxxxxxxxxxxx>
>>Charles Francis <charles@xxxxxxxxxxxxxxxx> writes
>>>Thus spake Oz <Oz@xxxxxxxxxxxxxxxxxxxx>
>
>>>>Try connecting a transformer without the iron core to the mains and then
>>>>you will see how important the inductance is.
>>>
>>>I think I would have difficulty. I have noticed that the coil is
>>>generally tightly bound to the iron core, so that I would have trouble
>>>extracting it.
>>
>>Usually not that hard once you have ground off a short bead of weld (if
>>any). The sections are usually lots of thin "W" and "I" shaped sheets
>>stacked together. That's how they assemble them over the bobbin of
>>course.
>>
>>>If I did get the wire off it really would be just a load
>>>of heating wire.
>>
>>Incompetent fool.
>
>Oh, I thought you wanted me to extract the core leaving the coil
>undamaged.

Yes I did. Its the reverse of the procedure for putting the core inside
the bobbin.

For the ER & I laminations see
http://www.osbornetransformer.com/s_designoptions.shtml
>
>>High voltahe spikes will likely be bad news for insulation arc-over and
>>once an arc is made ...
>
>A surge protector was the first suggestion. Jim can read the entire
>thread and find out it just gets back to where it started. What fun for
>him!

Surge protectors can themselves blow, some are better than others.

>>>Duh. This was in a cooker in a largish kitchen.
>>
>>Why did they put a transformer in the oven.
>>Wouldn't it have been better placed outside the insulation in a cool
>>place with wires run to the ignitor?
>
>Funny thing is, you know, they tried that design too. It was the one we
>had trouble with. That must be why they put it in the oven on later
>models.
>
>[mind you, the whole thing does warm up a little, probably not
>excessive]

Isn't an oven supposed to be hot?

>>>It's designed to get
>>>hot, or it wouldn't be very good for cooking. The transformer was only
>>>used to ignite the burners, and then only briefly. There was therefore
>>>no current through it except when the cooker was too cool.
>>
>>Unlikely to be much effected by a 10% (or even 20%) overvoltage then.
>
>It was fairly critical. An alternative transformer from a different
>manufacturer survived. The original and at least two direct replacements
>did not. Italian manufacturer. Of course their voltage is lower and they
>may have been duped into thinking we are on 230 volts, as that is what
>the regs appear to say.

I think its more likely that the design was duff, most likely the HV
insulation was improperly rated.

>Mind you, I'm damn glad I didn't get you in as a consultant. The
>electrickery company coughed up £1200+ without a fuss for the
>accumulated bills by the time the problem was sorted.

Lucky you....

--
Oz
This post is worth absolutely nothing and is probably fallacious.

Use oz@xxxxxxxxxxxxxxxxxxxx [ozacoohdb@xxxxxxxxxxxxx functions].
BTOPENWORLD address has ceased. DEMON address has ceased.

.

Relevant Pages

  • Re: About leakage inductance in transformers
    ... the core, but to maximise coupling to *each other*. ... layer of secondary windings, covered by tape, and then another layer ... worked for years since with no appreciable heat from the transformer. ... Saturation is possible in many cases where accepted design ...
    (sci.electronics.design)
  • Re: Converting Switching Power Supply for Inductive Heating
    ... You need to design the coil to suit the job your trying to do, ... The smps transformer will only work near it's design frequency, ... It's highly likely to destroy the smps. ...
    (sci.electronics.misc)
  • Re: Core power handling Capability
    ... Simply increasing the frequency may reduce flux peaks, but core loss ... This is pretty well all they have for the transformer. ... article, in which topology, operating frequency, input voltage range, ... transformer design issues. ...
    (sci.electronics.design)
  • Re: Transformer flux imbalande solutions
    ... Or a gapped ETD49 or 59 core may be the thing aswell? ... magnetizing current as transformer current. ... When you approach the limits it is a softer entry into hard saturation. ... long as you're careful with the design I don't think flux walk will be a ...
    (sci.electronics.design)
  • =?ISO-8859-1?Q?Re=3A_DIY_electromagnet_under_=A3100=3A_Disappointing_res?= =?ISO-8859
    ... an electromagnet under £100, with the strongest and cheapest one ... The transformer E I core. ... Consider this setup, a normal transformer core: ... So, just a single bolt will not do much in a coil, except pull it to ...
    (sci.electronics.design)