Re: Robby the Robot installed (Hallmark version)

On Oct 8, 6:53 pm, beaver <e...@xxxxxxxxxxxx> wrote:
Ok, I will try and find some time to draw this up.

Edward Cheung CARGPB26

On Oct 8, 6:26 pm, Joey <joefehrenb...@xxxxxxxxx> wrote:



On Oct 8, 1:17 pm, beaver <e...@xxxxxxxxxxxx> wrote:

On the lamp matrix, lamps that are selected (row and column drivers
on) will have a positive voltage across them.  By symmetry, those
lamps that are _not_ selected will have a certain amount of negative
voltage across them.  The amount will vary from case to case.  By
putting diodes in series with lamps, only those lamps that are
selected will turn on.  That is why diodes are used in the lamp
matrix.

LEDs, although they are diodes, are made to be bright, and not to be
able to withstand negative voltages.  Usually, they can tolerate less
than 10V (or even less than 5V).  So the series diode that I put in
all my mods is to protect the LED from the reverse voltage.

Edward Cheung CARGPB26

On Oct 8, 2:43 pm, Joey <joefehrenb...@xxxxxxxxx> wrote:

On Oct 8, 10:40 am, beaver <e...@xxxxxxxxxxxx> wrote:

There is just one resistor and one diode.  Both are in series with the
column (+ side) wire.  The diode faces the "correct" way (of course),
and the resistor is 51 ohms.

I put the diode into the body.  However, the resistor I put under the
playfield.  This way, I could tweak the value without taking
everything apart!

Why did you do a diode and resistor? Not questioning your judgement as
I know you know what you're doing. I'm just curious if I am wrong in
how I plan to wire mine up. I was just planning on tapping into the GI
lighting and wiring in a 150 ohm resistor on the positive lead to each
LED to bring the LED forward voltage down to 3.4. Is there a better
advantage to using a diode with a smaller ohm resistor?- Hide quoted text -

- Show quoted text -

I had no idea. Any chance you could include this diode and resistor
info on your site? I imagine there's a lot of folks like me with very
limited electronic experience and could use a step-by step on the
wiring.
Oh, and I hope I don't sound ungrateful. Your TZ Robby write up is
awesome.- Hide quoted text -

- Show quoted text -

That would be great if you could, Ed! Rick, I'm not sure what you mean
by not connecting to a row wire.
My plan was to do the following:

-Yellow portion in the torso gets connected to the Super Skill insert
light using a 3mm yellow or amber LED (connect the positive 'anode'
side to the Super Skill light power - not sure where to connect the
negative 'cathode' side). Use a 150 ohm resistor to drop the 6.3v to
~3.4v.
As an alternative, I have amber 555 6.3v bulbs from bcspinball. I'm
just not sure yet if there's enough room in the body for one of these
though..

-Blue portion in the "mouth" gets connected to the Multi Ball insert.
I was thinking I could just use a blue 555 6.3v LED that I purchased
from bcspinball and just have laying around. Obviously, no resistor is
required. I was going to wire + and - directly to the multiball
insert.

_White "head" light gets connected to the Bonus X insert using a 3mm
white LED (connect the positive 'anode' side - not sure where to
connect the negative 'cathode' side). Use a 150 ohm resistor to drop
the 6.3v to ~3.4v.

Also, it sounds as though all three LEDs can share a common ground?
I'm assuming this since Ed's write up shows he has 3 LEDs and only
four total wires going to the Robby.

Anyway, I'm now pretty sure that the way I described above is not the
way to go. Ed, if you, or anybody else for that matter, can poke holes
in my plan and provide specifics for a better way to wire this guy up,
I'd really appreciate it.
Thanks again!
.

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