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Martin Jones Sync Pulse Generator: A Layman in Need of Help with a Schematic

I may just whip it up in Easy EDA with a schematic. Then you can at least have a better look at it.

I still need to perform a more thorough check of the FreePCB design which I uploaded here, the one that you're using, and triple check to ensure that I didn't make any errors.
 
@acblunden2

I've quickly whipped up a schematic and PCB in Easy EDA. It's a public project so you can view / modify / edit / order PCB's etc. Just type in SYNC as the search and look for a project named SYNC PULSE GENERATOR by Frank_fjs

I was in a rush so the schematic isn't neat but it should be accurate. Same deal re the PCB. Ill work on it more when time permits, but for now it's a good starting point.

SYNC-PULSE-GENERATOR_SCHEMATIC.png
SYNC-GEN-TOP.png
SYNC-GEN-BOTTOM.png
 
@acblunden That looks like a National Semiconductor part. There shouldn't be anything wrong with it assuming it is in good condition.
 
First rule of trouble-shooting, check your power (or lack of power in this case it seems 8) ). The schematic by Martin Jones was made in Altium Designer, and was probably posted just to explain the workings - not all the nuts & bolts. A complete schematic would have all the pins of all IC's..
 
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@Frank_fjs I can generate a schematic from the PCB I made and posted, which @acblunden2 has used successfully, when I return home. From a comparison there, any problems might stand out.

If you have a scope, then you could check the various inputs and outputs to see at what stage things fall apart. Martin's writeup is pretty clear:

Martin Jones' said:
IC1B is a monostable which triggers on every sync pulse, generating a pulse 4.7 microseconds long. These become the new horizontal sync pulses.
IC2B combined with D1, R3 and C3 form a sync separator which triggers the monostable in IC1C only on sync pulses which are longer than about 40 microseconds.
IC1C is a monostable which generates vertical sync pulses about 200 microseconds long.
IC2E combines the new horizontal and vertical sync pulses into a new sync signal.
Click to expand...
 
Tell you guys what. I am going to put an order in for Mike's version of the Sync Pulse Generator. It is known to work. I think there are some fellas standing on the sidelines that want to see this working to solve for their problems. So allow me to move forward with that. I'm cool with continuing to troubleshoot Frank's work in parallel. And of course, XianXi can continue to update us with his particular application.

We can halt the troubleshooting too since Mike's PCB is available. I don't want to use up too much of everyone's talents and time either. You've all been far to gracious with lending your assistance. Thank you. I know Frank has some other projects that need his attention right now. Mike is always working on Gimmick too.

P.S.: no scope @Hatsune Mike.
 
acblunden2 said:
I know Frank has some other projects that need his attention right now.
Click to expand...
Well he kinda shot down my idea of a proper multi JAMMA switcher PCB that utilized his existing JAMMA + Kicks Extender design.

So the miniGun is the focus now? I've gotta tell ya, the name is waaay cooler than the actual device.
We've got superguns, lots of 'em now... So yea, waste his time with a sync generator, IMO its just being wasted anyway. /dickmodeoff

Expected...
GVxtkv7.jpg
 
I didn't shoot it down, did I? Last I recall I asked for someone to make a discussion thread so we could toss around ideas on the best and safest way to implement it. No such thread has been created.

My ideas thus far are a central board with vertical jamma connectors. A variety of power input options / connectors and physical switches to select the active game. Jamma extenders to interconnect between the central switcher board and game PCBs.

I admit I've taken you the wrong way in the past, @jassin000, but getting to know you better I can conclude that you're not a dick, just a passionate individual who knows what they want. :)

Re the Minigun, it has its place I feel. Low cost and quick and easy to assemble. I like the idea of it being open source so many minds can collaborate and offer improvement. I'm hoping it offers a way to put superguns in the hands of people who don't want to outlay 100s of dollars or wait lengthy periods of time on waiting lists.

Yes please @Hatsune Mike re your offer of a schematic.

Sorry I let you down @acblunden2, feel free to poke around the Easy EDA design I've made public. I'll continue to work on it as I'm determined to get it working.
 
It will be easy for me to test too as I have headers on my supergun for power and sync, so I can just patch in the sync board via jumper cables.
 
I soldered resistors to the surface of one of the Osh Park PCB's I ordered. Those were the ones that had through holes that were too small to use. Tested it to see if maybe the JLC productions were the problem. No luck there either.

Will await Mike's PCBs and use the same components on those.
 
I must have made an error in my original PCB. Probably something simple but easy to overlook.

This latest PCB I generated from a schematic so fingers crossed it works as expected. I'm going to test it with F3 via scart and OSSC, want to see if it works.
 
Nice, can you tell us what the changes were to make it work ?
 
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