PET composite video adapter
ethan.dicks at usap.gov
Mon Oct 13 13:48:14 CDT 2008
On Mon, Oct 13, 2008 at 09:46:01AM -0700, Chuck Guzis wrote:
> On 13 Oct 2008 at 4:08, Ethan Dicks wrote:
> > The schematic shows the horizontal sync coupled to a gate via a "2200 mf"
> > non-polarized cap. I don't know that I have any disc or ceramic caps that
> > large lying around. The output of that gate (which NORs the inverted
> > vertical sync with the massaged horizontal sync) feeds unto a "47mf"
> > tantalum cap (then pulled down to ground by a diode, and wire-ored to
> > inverted video out/composite out via a 470 Ohm resistor). I have 47uF caps,
> > but that seems pretty large to me.
> That 2200mf is off by at least 3 orders of magnitude. 0.22 uF is
> probably more like it.
I can entirely believe that. What I'm wondering is if the original
article should have read 2200pF.
> The 47 uF might be okay, but I suspect that
> 4.7 uF may also work just fine. (But I don't have your circuit, so
> it's really difficult to say for certain).
> It's been a long time since I wired up one of these, but ISTR that I
> didn't find component values to be very critical.
Glad to hear it. I'm going to build the first version on a proto board
so it will be easy to swap out caps.
Ethan Dicks, A-333-S Current South Pole Weather at 13-Oct-2008 at 18:40 Z
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Ethan.Dicks at usap.gov http://penguincentral.com/penguincentral.html
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