Osirus wrote:The sync input you apply your sync to should already have its own 750 ohm termination if you apply your sync to the composite input. No need for any resistors there.DemoNight wrote:
Thanks for the reply, i'll leave the diodes out since the math is already done for me to not have them. Though, and this is more of a theory question then a question for this project, but I don't understand how a diode will effect resistor values in this case. If I go both resistors, then a diode on the cricut back to the microcontroller how does that affects the resistance on the circuit going to the jungle?
Anyways, my only other question is for sync, do I need to add resistors to that? I plan to solder onto the back side of the composite input to a female scart plug that i'm going to mount in the case. Actually, two more questions come to mind if that's ok. First, I read a few people say the resistors on the RGB input should be resistors to ground, I won't even bother to ask why that makes a difference but with this version of the mod I should ground all 3 signal wires with a 75ohm resistor for each (and to be super clear we are talking the grounds on the scart plug, i'm planning to ground the scart plug itself to the same composite ground), do I still need that 0.01 cap in that circuit I see other people use? Then have the signal wires run to that 330ohm resistor then bring the output of that into the Micro to Jungle chip circuit, do I have that right?
And for that L003 inductor, i'm going to apply 5v to the input side of that inductor with a 470ohm to blank the screen, is that right?
The RGB inputs you add need to have 75 ohm resistors to ground. That's standard for analog video signals. It will match the output impedance of the devices you connect to the tv. If you look at the composite, s-video, or component inputs that the tv already has they will also measure 75ohm to ground.
What you said about the 470ohm resistor to the L003 inductor sounds right, without looking.
Thanks, plan to prototype this on a breadboard first, confirm it's working right then hard wire it into the set. I'm in way over my head. I've done some basic mod chip on console installs before but nothing like this. I looked for someone local to do the mod for me but couldn't find anyone, thanks for spending time helping me.