33V stabliizsers - PH33J AND 33G - differences?
b
can I use a PH33J when a 33G is recommended?
then only references I found online were commercial sites with no
datasheets
TIA
B
ian field
"b" <reveren...@yahoo.com> wrote in message
news:573918d8-1cdd-4803...@q11g2000yqh.googlegroups.com...
Generally speaking you can use any of the different manufacturers parts so
long as its specified for use as a 33V tuner varicap supply stabiliser.
Franc Zabkar
<reveren...@yahoo.com> put finger to keyboard and composed:
>this is a 33v stabilizer from a 14" tv set
Are you sure?
The following forum thread suggests that the PH-33J is equivalent to
the BYD33J, in which case your diode is not a "stabiliser":
http://www.forumnow.com.br/vip/mensagens.asp?forum=32226&topico=2630665
This site lists it under Schottky diodes:
http://chinaimportexport.wikispaces.com/China+Diodes+Manufacturer+Stock+price+List+-+China+integrated+circuits,IC,Diodes
Confusingly, this stock list shows a PH-33V as a 33V 1W part:
http://www.rccomponent.com/class-121.pdf
A typical use for a 33V stabiliser would be in the tuning voltage
supply. Is this where it is used?
>can I use a PH33J when a 33G is recommended?
>then only references I found online were commercial sites with no
>datasheets
>
>TIA
>B
This list of Philips marking codes attributes a code of "33J PH" to
the BYD33J (fast soft-recovery controlled avalanche rectifier):
http://www.datasheetarchive.com/pdf/Datasheet-023/DSA00399242.pdf
Here is a datasheet for the BYD33 diode:
http://www.ilriparatore.it/pagine/varie/telai/philips61/BYD33_3.pdf
Assuming your PH33J is a Philips part, as suggested by a search at
http://www.usbid.com, then the above datasheet suggests that the
suffix denotes a particular rating, in this case the VRRM.
VRRM repetitive peak reverse voltage
------------------------------------
BYD33D - 200 V
BYD33G - 400 V
BYD33J - 600 V
BYD33K - 800 V
BYD33M - 1000 V
BYD33U - 1200 V
BYD33V - 1400 V
While the same suffix for a zener would be comparing different
parameters, it would at least appear that the J part has a better
rating than the G part.
- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
b
> On Wed, 25 Feb 2009 04:32:14 -0800 (PST), b
>
> >this is a 33v stabilizer from a 14" tv set
>
> Are you sure?
>
> The following forum thread suggests that the PH-33J is equivalent to
> the BYD33J, in which case your diode is not a "stabiliser":http://www.forumnow.com.br/vip/mensagens.asp?forum=32226&topico=2630665
>
>
> Confusingly, this stock list shows a PH-33V as a 33V 1W part:http://www.rccomponent.com/class-121.pdf
Thanks a lot for all the info. Hmm, looks like it may not be the right
thing.
Yes, this is in the 33v line to the tuner of the TV. it is replacing a
TAA 550. (symptoms: set searching but not finding anything, just snow.
Tuner supply down to about 5v)
not only that, but I fitted it this afternoon and tried the set, I got
a picture but tuning lock was unsteady especially when channels were
changed. To my surprise I measured some 50v on that line instead of
the usual 30v!
Obviously something is amiss. Apparently I can use a KA33V stabilizer
in lieu of the TAA 550, so I'll get one and see.
-B
Franc Zabkar
<reveren...@yahoo.com> put finger to keyboard and composed:
The 33V supply is probably derived from a rectified 50V pulse from the
flyback transformer. It most likely consists of a rectifier diode,
capacitor, series resistor, and the TAA550 33V precision zener.
If a reverse biased rectifier diode were installed in place of the
original TAA550, then the full 50V would have appeared on the supply
rail.
ian field
Some TVs use this (33V part): http://www.ebg-darmstadt.de/pdf/ZTK.pdf
b
>
> Some TVs use this (33V part):http://www.ebg-darmstadt.de/pdf/ZTK.pdf
I think that is what I mistook that part for. There is one thomson
chassis which uses it.
Anyway, after replacing the susepct regulator with the KA33V all is
well.