XPost: alt.home.repair, uk.d-i-y
From: snick@invalid.invalid
In article , "William
Gothberg"@internet.co.is says...
>
>On Wed, 19 Dec 2018 14:32:29 -0000, Snicker wrote:
>
>> In article , "William
>> Gothberg"@internet.co.is says...
>>>
>>> On Wed, 19 Dec 2018 14:23:48 -0000, William Gothberg <"William
Gothberg"@internet.co.is> wrote:
>>>
>>>> On Wed, 19 Dec 2018 12:51:53 -0000, Art Todesco
wrote:
>>>>
>>>>> On 12/19/2018 7:35 AM, William Gothberg wrote:
>>>>>> On Wed, 19 Dec 2018 12:18:54 -0000, Rod Speed
>>>>>> wrote:
>>>>>>
>>>>>>> William Gothberg <"William Gothberg"@internet.co.is> wrote
>>>>>>>
>>>>>>>> Those fake starters people put into fluorescent fittings when they
>>>>>>>> put in
>>>>>>>> an LED tube.... what's inside?
>>>>>>>
>>>>>>> A bit of wire between the pins.
>>>>>>>
>>>>>>>> An LED tube draws power from the two ends, I looked inside one of my
>>>>>>>> tubes
>>>>>>>> and the two pins at each end are shorted together.
>>>>>>>
>>>>>>> They don't all do it the same way.
>>>>>>>
>>>>>>>> The LED PSU takes power from both ends if you see what I mean, it
>>>>>>>> expects
>>>>>>>> live at one end and neutral at the other. So why on earth would you
>>>>>>>> need
>>>>>>>> anything in the starter, even if you left the ballast in?
>>>>>>>
>>>>>>> Because the simple bimetallic strip starters have the pins
>>>>>>> on the starter connected initially and not connected
>>>>>>> when it warms up due to the current between the pins.
>>>>>>>
>>>>>>>> Surely it's best to have the starter open circuit, i.e. just remove
it.
>>>>>>>
>>>>>>> Some do work like that.
>>>>>>>
>>>>>>>> Does it perhaps in some way negate the inductive nature of the
>>>>>>>> ballast to
>>>>>>>> be nicer to the LED PSU?
>>>>>>>
>>>>>>> No it does not. So its better, but not as easy, to disconnect the
>>>>>>> ballast as
>>>>>>> well.
>>>>>>
>>>>>> The properly made LED tubes are connected live at one end and neutral at
>>>>>> the other. You just remove the starter, and the LEDs operate in series
>>>>>> with the ballast (or directly to the mains if you can be bothered
>>>>>> opening the casing and shorting/removing the ballast).
>>>>>>
>>>>>> So the tubes where they have live and neutral on the same end, require
>>>>>> supplying a fake starter instead of just removing it, surely an
>>>>>> unnecessary extra expense. The only reason I can find for making them
>>>>>> like this is some daft safety regulation about having live and neutral
>>>>>> at opposite ends. Better insulation required to meet safety standards
>>>>>> incase you grab live and neutral with your two hands? Surely either the
>>>>>> casing of the LED tube is metal, which means you can't get a different
>>>>>> voltage on each hand, or plastic, which means it won't conduct power to
>>>>>> you.
>>>>> I just bought some LED 4' tubes that can be wired any way you want. I
>>>>> don't know the internal circuitry, but I do plan to dissect one to find
>>>>> out. These can be powered from one end (either one), both ends and,
>>>>> when powering from both ends, the pins can be shunted or not. There
>>>>> seems to be no combination that doesn't work!
>>>>
>>>> I can think of a way it might be connected, but please look inside to
satisfy our curiosity!
>>>>
>>>> Kinda like a bridge rectifier but with 4 inputs instead of 2 - any pin of
the tube being positive goes through a positive diode, any pin being negative
goes through a negative diode (as in connected backwards).
>>>>
>>>> You know, a diagram would be easier: https://www.dropbox.co
/s/clfblkmb6pyqyl8/tube.jpg?dl=0
>>>
>>> In fact they could just use two bridge rectifiers already in packages, and
connect one to one end of the tube and one to the other, with the output of
both connected to the PSU bulk capacitor. This would make the circuit I drew
above.
>>
>> Do you always answer yourself?
>
>I was adding information to my previous post. Was that too difficult for you?
Well stop acting like an attention whore.
--- SoupGate-Win32 v1.05
* Origin: you cannot sedate... all the things you hate (1:229/2)
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