Re: Scoping a SMPS primary side...
- From: Jim Yanik <jyanik@xxxxxxxxx>
- Date: 12 Oct 2005 23:21:07 GMT
The Schneids <news@xxxxxxxxxxxxx> wrote in
news:11kqj4o2dhagme7@xxxxxxxxxxxxxxxxxx:
> Kirk S. wrote:
>> Hi,
>>
>> I'm trying to figure out a dead monitor power supply that uses a
>> UC3842B controller. I'd like to hook my scope to the chip and
>> observe any signals during startup, etc. Since this is connected to
>> rectified line voltage on the ground plane and a large power resistor
>> on the vcc line, I'm unsure where to hook my ground for the scope
>> probe. I'm using an isolation transformer, variac and series light
>> bulb in addition to the scope.
>>
>> I'm just a tinkerer used to scoping clock signals on TTL circuits and
>> hesitant to do something that will toast my scope.
>>
>> Any suggestions? Oh yeah, no schematics for the monitor either. I'm
>> looking at a similar schematic using the same control chip. I see
>> the startup voltage of +16vdc and no reference voltage or output
>> strobe signals.
>>
>> Help!
>>
>> Kirk S.
>>
>>
>
> I've worked on these a lot - I don't use the scope anymore.
> When I did, I made sure the ground of the scope was floating -
The WRONG way.
You're supposed to isolate the DUT,not the test equipment.
> use one of those 2 prong to 3 prong adapters to isolate the
> ground.
Leaving the scope chassis potentially HOT,a clear hazard.
--
Jim Yanik
jyanik
at
kua.net
.
- Prev by Date: Re: Zenith Z27a11s inputs
- Next by Date: Re: Telephone tap
- Previous by thread: Re: Scoping a SMPS primary side...
- Next by thread: Re: Scoping a SMPS primary side...
- Index(es):
Relevant Pages
|
