🚀 go-pugleaf

On 16 May 2005 05:20:33 -0700, "alitonto" <alitonto@hotmail.com> put
finger to keyboard and composed:

>Hello Frank,
>That's the direction I was thinking but wasn't sure if anything in
>particular needed to be observed. For example the schematics I obtained
>from DSE, thnks for your previous reply, indicate that the volts to the
>base of the HOT needs to be 0.34; therefore would I be correct in
>thinking that the existing circuit board will produce that if I select
>a close enough match for the driver transformer?
>Cheers
>A.T.

AFAICS, any 12V HDT that is designed to drive an NPN transistor should
be suitable. That's just about all of them. One caveat may be that
some HOTs have a lower hfe than others, which would mean they would
require more base current. A symptom of low drive would be a hot HOT.
Just to be safe, I'd run the set for a minute or so and then check the
HOT temperature.

>Franc Zabkar wrote:
>> On 15 May 2005 06:15:10 -0700, "alitonto" <alitonto@hotmail.com> put
>> finger to keyboard and composed:
>>
>> >I have  Digitor 12 volt TV Model G7200 year 1993 from Dick Smith
>> >Electronics for which the H.D.Transformer is no longer available
>from
>> >spare parts. (Checked with DSE).
>> >I am thinking what specs to look for if I was to find a spare part
>in
>> >my parts box.
>> >Would this be possible at all?
>> >It drives the HOT which is a BU407 and the chip on the board is an
>> >LA7680 where pin 27 supplies the signal.
>> >Any expertize here will be welcome.
>> >Thks
>> >A.T.
>>
>> Try adapting a transformer from a current model 12V TV. I would
>> imagine they would be mechanically different but electrically similar
>> (same B+, same frequency, similar output).
>>
>>
>> - Franc Zabkar
>> -- 
>> Please remove one 's' from my address when replying by email.


- Franc Zabkar
-- 
Please remove one 's' from my address when replying by email.