VIPer12A power circuit problem
Panda
I'm using VIPer12AS-E to designing a AC-DC Power, 85-240VAC input and
12VDC,500mA output.
I found a circuit from ST website, see 1.jpg here:
http://3921990887528268634-a-protectanimals-com-s-sites.googlegroups.com/a/protectanimals.com/temp/Home/1.JPG?attredirects=0&auth=ANoY7crMjjB0FW2rw-C3KadOEzgTOJ6jFaVBwc9zqeFXz8Ryv8x6e-QA2PB_88XepSlITDwe-ny04Jt_3llbJXJgCDxJxoGFI8Xv5owk-9ncL9opLvUb363-EJ-0koIbFgovC6NFcbsv3U98s3WTEdJYMEFcFDg2wOfwBUM4zPNEg1PRLCjFDsjzV3vWUYM3iRk50rgE9QGm
And i reduced this circuit, see 2.jpg here:
http://3921990887528268634-a-protectanimals-com-s-sites.googlegroups.com/a/protectanimals.com/temp/Home/2.JPG?attredirects=0&auth=ANoY7cqXB4me6XlxTjo52wZnGWvPQ0TRVwhiLmLJy2ARddWtRpOIR2nfnTgDwJWm-XFNI3kZHGQQ36BHa9kJLGmAmULlxv_Ir4S9kuz5R9ExRnBqNe49Cg8DZVRDTNEIeJidxaOdAXja4qH5V3QrFQG8ahyOCWOmJeVVTJmN9EleihlNGuNfIlfGZ5hquoA1mDSxGVfzv2UD
Since I don't have a ultrafast high voltage rectifier STTH1L06 yet, I
use normal schottky power rectifier MURS140 instead(D17 in 2.jpg).
And for safty, I did not solder C75,C76,C77 in the 12VDC side.
Now I use multimeter measure the 12VDC, just get 1.4VDC.
And when I use oscilloscope, I got a wave like this:
http://3921990887528268634-a-protectanimals-com-s-sites.googlegroups.com/a/protectanimals.com/temp/Home/3.JPG?attredirects=0&auth=ANoY7cpobQzABIz1jIGqVoXz-jra3FqI69Bt3ebJj_fRec_otMi1VaAUctOb5m9KN12lvwyD1P2zOSFlnQeIdSicToPvdAquaSDrR1X8-VlAodgzv6G-GuJTywpG2iMv00-4patA2RZ3jNG0A33tWwewa4WpAV12CNcWPHOBaLgtM51Wq3uNevnqK9U9nYZsua_OcvaCjOsg
I'm confused, and do not which part is wrong?
And I don't know what exactly R45,C70 do?
Can anyone give me some hint？
Thanks in advance!
Hammy
<pa...@protectanimals.com> wrote:
>Hi All,
>
>I'm using VIPer12AS-E to designing a AC-DC Power, 85-240VAC input and
>12VDC,500mA output.
>I found a circuit from ST website, see 1.jpg here:
>http://3921990887528268634-a-protectanimals-com-s-sites.googlegroups.com/a/protectanimals.com/temp/Home/1.JPG?attredirects=0&auth=ANoY7crMjjB0FW2rw-C3KadOEzgTOJ6jFaVBwc9zqeFXz8Ryv8x6e-QA2PB_88XepSlITDwe-ny04Jt_3llbJXJgCDxJxoGFI8Xv5owk-9ncL9opLvUb363-EJ-0koIbFgovC6NFcbsv3U98s3WTEdJYMEFcFDg2wOfwBUM4zPNEg1PRLCjFDsjzV3vWUYM3iRk50rgE9QGm
>
>And i reduced this circuit, see 2.jpg here:
>http://3921990887528268634-a-protectanimals-com-s-sites.googlegroups.com/a/protectanimals.com/temp/Home/2.JPG?attredirects=0&auth=ANoY7cqXB4me6XlxTjo52wZnGWvPQ0TRVwhiLmLJy2ARddWtRpOIR2nfnTgDwJWm-XFNI3kZHGQQ36BHa9kJLGmAmULlxv_Ir4S9kuz5R9ExRnBqNe49Cg8DZVRDTNEIeJidxaOdAXja4qH5V3QrFQG8ahyOCWOmJeVVTJmN9EleihlNGuNfIlfGZ5hquoA1mDSxGVfzv2UD
>
>Since I don't have a ultrafast high voltage rectifier STTH1L06 yet, I
>use normal schottky power rectifier MURS140 instead(D17 in 2.jpg).
>And for safty, I did not solder C75,C76,C77 in the 12VDC side.
>
>Now I use multimeter measure the 12VDC, just get 1.4VDC.
>And when I use oscilloscope, I got a wave like this:
>http://3921990887528268634-a-protectanimals-com-s-sites.googlegroups.com/a/protectanimals.com/temp/Home/3.JPG?attredirects=0&auth=ANoY7cpobQzABIz1jIGqVoXz-jra3FqI69Bt3ebJj_fRec_otMi1VaAUctOb5m9KN12lvwyD1P2zOSFlnQeIdSicToPvdAquaSDrR1X8-VlAodgzv6G-GuJTywpG2iMv00-4patA2RZ3jNG0A33tWwewa4WpAV12CNcWPHOBaLgtM51Wq3uNevnqK9U9nYZsua_OcvaCjOsg
>
>I'm confused, and do not which part is wrong?
>And I don't know what exactly R45,C70 do?
>Can anyone give me some hint?
>Thanks in advance!
>
>P.S. the transfomer's datasheet is here:
>http://3921990887528268634-a-protectanimals-com-s-sites.googlegroups.com/a/protectanimals.com/temp/Home/s06100057.pdf?attredirects=0&auth=ANoY7cp_Tay0a-czHjan_WQWLY5wnCeiFio2cm75XcX9C2qOIyBLa8Ii1NRwcETp1hgT5TXnV5JBxrcSPZk6WR60xZUbDD_O5u2433OoB4FYszrxiBvrx1XmOKUXoElmUcUVq3_GV28wvLWOexOYXQK5vZ4nOgBm4QdBHbqTO4ghoCr5qH0ueycqYi-4m2lbwOS9eGCKrdYqr-Ko3O_ILs4nRsf4RG7gMg%3D%3D
One obvious thing is if you actually have it wired as you've drawn it
your secondary is shorted pin 8 and 5 of your transformer.Assuming
everything else is correct your converter might be going into current
limit burst mode.I'm not familiar with the Viper controllers but some
controllers will limit the output power by going into burst mode in
the event of a short.
C70 and R45 with D17 form an RCD snubberyou have to clamp the drain
voltage a flyback has leakage inductance.You can google RCD snubber
flyback. For your power level you could have also used a zener (TVS)
clamp for the drain.
Hammy
>On Thu, 5 Feb 2009 02:59:40 -0800 (PST), Panda
><pa...@protectanimals.com> wrote:
>
>>Hi All,
>>
>>I'm using VIPer12AS-E to designing a AC-DC Power, 85-240VAC input and
>>12VDC,500mA output.
>>I found a circuit from ST website, see 1.jpg here:
>>http://3921990887528268634-a-protectanimals-com-s-sites.googlegroups.com/a/protectanimals.com/temp/Home/1.JPG?attredirects=0&auth=ANoY7crMjjB0FW2rw-C3KadOEzgTOJ6jFaVBwc9zqeFXz8Ryv8x6e-QA2PB_88XepSlITDwe-ny04Jt_3llbJXJgCDxJxoGFI8Xv5owk-9ncL9opLvUb363-EJ-0koIbFgovC6NFcbsv3U98s3WTEdJYMEFcFDg2wOfwBUM4zPNEg1PRLCjFDsjzV3vWUYM3iRk50rgE9QGm
>>
>>And i reduced this circuit, see 2.jpg here:
>>http://3921990887528268634-a-protectanimals-com-s-sites.googlegroups.com/a/protectanimals.com/temp/Home/2.JPG?attredirects=0&auth=ANoY7cqXB4me6XlxTjo52wZnGWvPQ0TRVwhiLmLJy2ARddWtRpOIR2nfnTgDwJWm-XFNI3kZHGQQ36BHa9kJLGmAmULlxv_Ir4S9kuz5R9ExRnBqNe49Cg8DZVRDTNEIeJidxaOdAXja4qH5V3QrFQG8ahyOCWOmJeVVTJmN9EleihlNGuNfIlfGZ5hquoA1mDSxGVfzv2UD
>>
>>Since I don't have a ultrafast high voltage rectifier STTH1L06 yet, I
>>use normal schottky power rectifier MURS140 instead(D17 in 2.jpg).
>>And for safty, I did not solder C75,C76,C77 in the 12VDC side.
The MURS140 is a 1A ultrafast ,you would fry a shottky if you used it
there.
You need those capacitors on the output thats how an SMPS works the
caps supply the load when the switch is off.
Panda
> On Thu, 5 Feb 2009 02:59:40 -0800 (PST), Panda
>
>
>
> <pa...@protectanimals.com> wrote:
> >Hi All,
>
> >I'm using VIPer12AS-E to designing a AC-DC Power, 85-240VAC input and
> >12VDC,500mA output.
> >I found a circuit from ST website, see 1.jpg here:
>
> >And i reduced this circuit, see 2.jpg here:
>
> >Since I don't have a ultrafast high voltage rectifier STTH1L06 yet, I
> >use normal schottky power rectifier MURS140 instead(D17 in 2.jpg).
> >And for safty, I did not solder C75,C76,C77 in the 12VDC side.
>
> >Now I use multimeter measure the 12VDC, just get 1.4VDC.
> >And when I use oscilloscope, I got a wave like this:
>
> >I'm confused, and do not which part is wrong?
> >And I don't know what exactly R45,C70 do?
> >Can anyone give me some hint?
> >Thanks in advance!
>
> >P.S. the transfomer's datasheet is here:
>
> One obvious thing is if you actually have it wired as you've drawn it
> your secondary is shorted pin 8 and 5 of your transformer.Assuming
> everything else is correct your converter might be going into current
> limit burst mode.I'm not familiar with the Viper controllers but some
> controllers will limit the output power by going into burst mode in
> the event of a short.
>
> C70 and R45 with D17 form an RCD snubberyou have to clamp the drain
> voltage a flyback has leakage inductance.You can google RCD snubber
> flyback. For your power level you could have also used a zener (TVS)
> clamp for the drain.
Thank you hammy,
Sorry for uploaded the wrong schematics.
I re-upload the sch here:
http://3921990887528268634-a-protectanimals-com-s-sites.googlegroups.com/a/protectanimals.com/temp/Home/4.JPG?attredirects=0&auth=ANoY7coKQxB7YpHAR1hn-nYJWIW90iC_SqmjbpY0qFNc0AGJT1v9KZBjbqgv7IVN-ONDFEGExObPDx_e7SqBIKshw00a2DmOpHs04qJM-HBIjLhQhaLfVcJEU_HF83M58RDXMryiCWMOosVV1pVXeWdv-2w0rZ00PMY0vKe-fD5j84Ek_KclOC5X7Yu-uEw7D2tWYp-tJT8i
Actually In my sch, I did not short the Pin 5,8 of the transformer.
legg
<pa...@protectanimals.com> wrote:
>Hi All,
>
>I'm using VIPer12AS-E to designing a AC-DC Power, 85-240VAC input and
>12VDC,500mA output.
>I found a circuit from ST website, see 1.jpg here:
>http://3921990887528268634-a-protectanimals-com-s-sites.googlegroups.com/a/protectanimals.com/temp/Home/1.JPG?attredirects=0&auth=ANoY7crMjjB0FW2rw-C3KadOEzgTOJ6jFaVBwc9zqeFXz8Ryv8x6e-QA2PB_88XepSlITDwe-ny04Jt_3llbJXJgCDxJxoGFI8Xv5owk-9ncL9opLvUb363-EJ-0koIbFgovC6NFcbsv3U98s3WTEdJYMEFcFDg2wOfwBUM4zPNEg1PRLCjFDsjzV3vWUYM3iRk50rgE9QGm
>
>And i reduced this circuit, see 2.jpg here:
>http://3921990887528268634-a-protectanimals-com-s-sites.googlegroups.com/a/protectanimals.com/temp/Home/2.JPG?attredirects=0&auth=ANoY7cqXB4me6XlxTjo52wZnGWvPQ0TRVwhiLmLJy2ARddWtRpOIR2nfnTgDwJWm-XFNI3kZHGQQ36BHa9kJLGmAmULlxv_Ir4S9kuz5R9ExRnBqNe49Cg8DZVRDTNEIeJidxaOdAXja4qH5V3QrFQG8ahyOCWOmJeVVTJmN9EleihlNGuNfIlfGZ5hquoA1mDSxGVfzv2UD
>
>Since I don't have a ultrafast high voltage rectifier STTH1L06 yet, I
>use normal schottky power rectifier MURS140 instead(D17 in 2.jpg).
>And for safty, I did not solder C75,C76,C77 in the 12VDC side.
>
>Now I use multimeter measure the 12VDC, just get 1.4VDC.
>And when I use oscilloscope, I got a wave like this:
>http://3921990887528268634-a-protectanimals-com-s-sites.googlegroups.com/a/protectanimals.com/temp/Home/3.JPG?attredirects=0&auth=ANoY7cpobQzABIz1jIGqVoXz-jra3FqI69Bt3ebJj_fRec_otMi1VaAUctOb5m9KN12lvwyD1P2zOSFlnQeIdSicToPvdAquaSDrR1X8-VlAodgzv6G-GuJTywpG2iMv00-4patA2RZ3jNG0A33tWwewa4WpAV12CNcWPHOBaLgtM51Wq3uNevnqK9U9nYZsua_OcvaCjOsg
>
>I'm confused, and do not which part is wrong?
>And I don't know what exactly R45,C70 do?
>Can anyone give me some hint?
>Thanks in advance!
>
>P.S. the transfomer's datasheet is here:
>http://3921990887528268634-a-protectanimals-com-s-sites.googlegroups.com/a/protectanimals.com/temp/Home/s06100057.pdf?attredirects=0&auth=ANoY7cp_Tay0a-czHjan_WQWLY5wnCeiFio2cm75XcX9C2qOIyBLa8Ii1NRwcETp1hgT5TXnV5JBxrcSPZk6WR60xZUbDD_O5u2433OoB4FYszrxiBvrx1XmOKUXoElmUcUVq3_GV28wvLWOexOYXQK5vZ4nOgBm4QdBHbqTO4ghoCr5qH0ueycqYi-4m2lbwOS9eGCKrdYqr-Ko3O_ILs4nRsf4RG7gMg%3D%3D
Apart from drawing errors around the transformer - could your zener be
inserted backwards?
The scope waveform needs re-examination, before and after the
rectifier (DC coupled) as a 50V peak output from the transformer is
unlikely to produce 1V4 after the rectifier - your multimeter may also
be giving an average value that the scope can resolve dynamically.
RL
Hammy
He said he doesnt have the output filter capacitors soldered for
safety?
Did you put the capacitors in?
legg
It would explain the abnormally high voltage.
There's no 'safety' reason to leave these parts out, and the circuit
will not function as expected without them. The primary clamp and
switch will also be overstressed if they are missing.
RL
Panda
> On Fri, 06 Feb 2009 16:48:22 -0500, legg <l...@nospam.magma.ca> wrote:
> >On Thu, 5 Feb 2009 02:59:40 -0800 (PST), Panda
> ><pa...@protectanimals.com> wrote:
>
> >>Hi All,
>
> >>I'm using VIPer12AS-E to designing a AC-DC Power, 85-240VAC input and
> >>12VDC,500mA output.
> >>I found a circuit from ST website, see 1.jpg here:
>
> >>And i reduced this circuit, see 2.jpg here:
>
> >>Since I don't have a ultrafast high voltage rectifier STTH1L06 yet, I
> >>use normal schottky power rectifier MURS140 instead(D17 in 2.jpg).
> >>And for safty, I did not solder C75,C76,C77 in the 12VDC side.
>
> >>Now I use multimeter measure the 12VDC, just get 1.4VDC.
> >>And when I use oscilloscope, I got a wave like this:
>
> >>I'm confused, and do not which part is wrong?
> >>And I don't know what exactly R45,C70 do?
> >>Can anyone give me some hint?
> >>Thanks in advance!
>
> >>P.S. the transfomer's datasheet is here:
>
> >Apart from drawing errors around the transformer - could your zener be
> >inserted backwards?
>
> >The scope waveform needs re-examination, before and after the
> >rectifier (DC coupled) as a 50V peak output from the transformer is
> >unlikely to produce 1V4 after the rectifier - your multimeter may also
> >be giving an average value that the scope can resolve dynamically.
>
> >RL
>
> He said he doesnt have the output filter capacitors soldered for
> safety?
>
> Did you put the capacitors in?
Thanks a lot Hammy.
Since I got a worrying scope without the capacitor, I'm a little worry
about the result of solder the 470uf cap on the output side.
I just soldered this cap right now, and the output looks right！
Thanks a lot all.
Panda
> On Thu, 05 Feb 2009 06:37:02 -0500, Hammy <spa...@hotmail.com> wrote:
> >On Thu, 5 Feb 2009 02:59:40 -0800 (PST), Panda
> ><pa...@protectanimals.com> wrote:
>
> >>Hi All,
>
> >>I'm using VIPer12AS-E to designing a AC-DC Power, 85-240VAC input and
> >>12VDC,500mA output.
> >>I found a circuit from ST website, see 1.jpg here:
>
> >>And i reduced this circuit, see 2.jpg here:
>
> >>Since I don't have a ultrafast high voltage rectifier STTH1L06 yet, I
> >>use normal schottky power rectifier MURS140 instead(D17 in 2.jpg).
> >>And for safty, I did not solder C75,C76,C77 in the 12VDC side.
>
> The MURS140 is a 1A ultrafast ,you would fry a shottky if you used it
> there.
> You need those capacitors on the output thats how an SMPS works the
> caps supply the load when the switch is off.
Yes, you are right. MURS140 can replace the ST ultrafast diode here.
And I really need those capacitors on the output and the caps can
supply the load,when the switch is off.