Re: Flyback Troubleshooting help

  Keep in mind that waveform in inherently flawed since that is *just
the primary* on the core and there *are no secondaries* at all (I took
them off)... so there shouldn't be any ringing because there is no
alternating field generation. I just realized that after I posted it.

I put the transformer back together and am rigging up a 555 oscillator
through a .047 cap to get a better voltage swing and current supply. I
will post some of those waveforms here in a bit. Initially, they are
looking odd.

The odd thing about this core set is that they are not glued and there
is no spacer. Torquing the little nuts on the core retaining bracket can
actually effect the ringing pattern... seems sorta lame.

On 1/17/2011 5:27 PM, John Robertson wrote:
> Jess Askey wrote:
>> Here is the main primary being rung @ 15KHz with a .047uf cap in
>> series with it, there are no other windings on the core with it...
>> but I can throw more on if needed.
>>
>> http://gamearchive.askey.org/Video_Games/Manufacturers/Atari/monitors/amplifone/raster/images/main_primary_ring_no_secondaries.jpg
>>
>> I thought that Raster flybacks where supposed to have spacers between
>> the cores? This one doesn't have any.
>>
>> jess
>>
>
> That image does not look good to me, the signal is damped way too
> quickly. You should see a train of decreasing rings like the other
> picture you posted. I suspect the red coil has a shorted winding after
> all - assuming you are only driving the red coil and it is out of
> circuit as in your most recent picture above.
>
> As for the spacer, it all depends on the design. I am fairly sure most
> flybacks do NOT have a spacer between the two halves, what they
> usually do have is some sort of glue...
>
> John :-#(#
>>
>> On 1/17/2011 2:35 PM, Rodger Boots wrote:
>>> Just grab a capacitor (.1 to 1 uF or so) and put it in series with
>>> the generator output. You just need to get rid of the DC component
>>> of the signal (transformers get weird around DC).
>>>
>>>
>>> On Mon, Jan 17, 2011 at 3:19 PM, Jess Askey <jess@askey.org
>>> <mailto:jess@askey.org>> wrote:
>>>
>>> My generator doesn't have a DC offset, I will have to build one.
>>> I just have a waveform generator IC that I breadboarded up
>>> really quick... I will see if I can get a waveform generator
>>> locally that has that feature.
>>>
>>>
>>> On 1/17/2011 2:16 PM, Rodger Boots wrote:
>>>> Does your generator have a knob marked "DC offset"? If so, set
>>>> it for a -4 to +4 volt square wave. Using 0 to +8 volts isn't
>>>> going to give you useful readings.
>>>>
>>>>
>>>> On Mon, Jan 17, 2011 at 2:19 PM, Jess Askey <jess@askey.org
>>>> <mailto:jess@askey.org>> wrote:
>>>>
>>>> Okay, I put the standalone LOPT onto my square wave
>>>> generator (unfortunately my generator can only supply 30ma)
>>>> so Im not sure that is enough.
>>>>
>>>> Here is the signal before attaching the LOPT.... 15KHz 9vP-P
>>>>
>>>> http://gamearchive.askey.org/Video_Games/Manufacturers/Atari/monitors/amplifone/raster/images/generator_output_15k.jpg
>>>>
>>>> Here is the primary with that signal attached...
>>>> secondaries are exactly the same waveform, yet in different
>>>> ratios (and those ratios are not correct)
>>>>
>>>> http://gamearchive.askey.org/Video_Games/Manufacturers/Atari/monitors/amplifone/raster/images/lopt_ringing_15k.jpg
>>>>
>>>> Doesn't look right.
>>>>
>>>> When I read a DC voltage on the Anode cap, I have 2.2VDC,
>>>> pretty low. :-(
>>>>
>>>
>
>
> --
> John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
> Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
> www.flippers.com
> "Old pinballers never die, they just flip out"

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Received on Mon Jan 17 19:57:56 2011