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Discussion Starter · #1 ·
I found a website with instructions on how to make a home made, digital, programmable ignition box for under $150. I'm pretty good with BASIC electronics, and feel I'm plenty competent to do this, but right now this is over my head and I don't know what everything means. For instance, what is a "27v mov" (MOV in the schematic)? And is Q1 in the schematic a MOSFET transformer? And what would I connect to "bypass" on "U3" in the schematic?

Even if this is a piece of you-know-what I still want to try to do this just for the hell of it.

Here's the address where this website is at.
 

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Just a little electronics terminology. Q - transistor (mosfet or otherwise) MOV = metal oxide varistor (kind of a voltage regulator), D = diode, C= capacitor (or condensor to some), U = chip or integrated circuit, X = transformer and of course R = resistor. With a brief look at the schematic, it appears that there are two U3's instead of a U3 and U4. I "think" that the reset from the U3 on the right, controls the output of the U3 on the left (what I would call U4 or "relay") The author would know for sure.
 

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Discussion Starter · #3 ·
Looking at the parts list, it seems like the author named the 2nd U3 wrong. Instead, the 2nd U3 should be U2. On the parts list, it calls for 2 of the SX28AC-DP (U2 and U4).

Thanks for your help... think this thing will work okay?
 

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Discussion Starter · #4 ·
Also, could someone tell me what the "spark in" and "spark out" connectors are for? I emailed the creator, but he hasn't responded yet.
 

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The 8 pin “U3” is the solid state relay. The 28 pin “U3” is, I believe, U2 one of the programmed microcontrollers that you buy from Mr. Riggs.

It looks to me like the “spark out”, “bypass“ and ”spark in” connections on U3 are the connections with the same identifications on U2 (28 pin U3), pins 10, 11 & 12.

The MOV (varistor) is an overvoltage/transient suppressor.


Newark part
U3- # 51F1742 (solid state relay)
MOV- #09F2204


Good luck with your project.
 

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Anyone have a preference for where to mount one of these? We've noticed some on this site prefer the engine bay, while others mount them under the dash on the inside firewall area (Some were right above the carpet area).

Our's is an Accel 300+ Digital CD Multi-Strike System with Rev Control, and it doesn't show a preference to which area.

If there's a link to a post on this subject, please let us know.

Any and all info greatly appreciated.

 
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