--
Iain
Aural perception is a skill that requires study and careful development
over
along period of time. Few have it as a natural gift.
"Ian Thompson-Bell" <ruffrecords@[EMAIL PROTECTED]
> wrote in message
news:ful4jg$1mmu$1@[EMAIL PROTECTED]
> Iain Churches wrote:
>> "Ian Thompson-Bell" <ruffrecords@[EMAIL PROTECTED]
> wrote in message
>> news:fukur1$1coj$1@[EMAIL PROTECTED]
>>> Iain Churches wrote:
>>>> "Eeyore" <rabbitsfriendsandrelations@[EMAIL PROTECTED]
> wrote in message
>>>> news:480DE286.CB70EB3C@[EMAIL PROTECTED]
>>>>> Iain Churches wrote:
>>>>>
>>>>>> The standard 6V3 winding would give 8.8V DC.
>>>>> Not with rectifier voltage drops it won't. More like 6.8V.
>>>> I did not include the rectifier losses.
>>>>
>>>> The AC is at about 235V here this afternoon. I have a
>>>> Welter mains transformer on the bench in front
>>>> of me. The heater winding is 6.3V at 3A reg 5%. With
>>>> a BR156 rectifier and 10 000µF and drawing 3A I measure
>>>> 7.6V across the electrolytic. What does a SS regulator
>>>> require?
>>>>
>>>> Iain
>>> Depends what you measure it with - a regular ac meter will not show
the
>>> ripple.
>>>
>>> Given c.dV = i.dt then dV(pp ripple) = i.dt/C and using your values I
>>> get
>>>
>>> dV = 3Ax10mS/10,000uF = 3V pp ripple!! assuming 50Hz mains and full
wave
>>> rectification.
>>>
>> Sorry, Ian. I was writing a post while doing ten other things at once.
>> Wives and secretaries can manage that admirably, I fail miserably:-(
>
> ROFL
>
>>
>> The heater supply chain has two caps with a low value WW pot between
>> them. C1 is 22 000µF and C2 is 10 000µF.
>>
>
> Ah, that's better, just over a volt ripple across the first cap and
> thereafter depends on the WW pot value, but since 3A is flowing it
cannot
> be more than a couple of ohms I guess.
The pot is a large multiturn WW, 5 Ohms IIRC
Regards
Iain
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