The J&S SafeGuard is an ignition timing controller that listens for knock then retards only the knocking cylinders.

Fair enough. I'm a small manufacturer, and make knock controllers for distributor and coil on plug ignition, with versions for dumb coils and for smart coils. I have a few videos on my channel showing operation. Originally this was going to be a retest of a customer's J&S SafeGuard. I don't use a script and since "it was a retest", didn't feel the need to explain the purpose of the system. The SafeGuard is an individual cylinder knock controller. He has the Universal version for distributor ignition.

“Automotive knock sensor test on oscilloscope”

​@@jselectronics8215maybe change the video titles to what the content means instead of the date?

@@koushiroizumi0 Yeah, sorry about that. KZbin puts the date in as a default when you forget to add a title.

Hi Garry,, yes, doing well, thanks.

Thank you. I'm almost afraid to drive it. After taking a hit, my Intrepid is officially a beater. The driver's door is a little crunched but it runs good.

My web page is jandssafeguard.com

Sandy, yes, this should work with any inductive ignition.

Cool, you found my company website?

If it hears a knock, it knows it had to be the cylinder that just fired, and that THAT cylinder won’t fire again for two more revolutions. When the knocking cylinder is about to fire again, software dials in the calculated amount of knock retard for THAT cylinder. Refer to this diagram from the “Tech” page on jandssafeguard.com www.jandssafeguard.com/images/KnockWindow.jpg

Thank you, Graham. I had to set the project aside while I cared for her. I have to finish it for her now. How can I fail?

Deepest condolences John. I've loved going through your videos, I've got the universal safeguard unit running in one of my cars and it's a great bit of tech for my old Hillclimb car here in South Australia 👍

​@@FizzaMC Jim: Thanks a million. I appreciate your your condolences and your support.

Is the Vampire 2 able to swallow the current through the primary wires? (this version 2 is awesome by the way). I love your testing set up too.

@@shortedtoground Yes, the Vampire "control wires" connect to the coil negative of each coil. The charged coil is like a hot potato. If you drop it, you WILL make a spark. When the rev limit trip point is detected, the rev limit transistor turns on hard, killing the flyback pulse. Then it is slowly turned off, effectively turning the transistor into a load resistor, allowing the energy stored in the coil to bleed off in a controlled manner. Only then can the transistor be turned off. Otherwise the coil will try to make a spark.

I made the video about a year ago. I had a lot of videos up but I accidentally deleted the channel. Everything is done in software, so I could add the feature at any time, but I don't see a real benefit, other than as a marketing gimmick. It looks cool, and was a challenge to program. "Hard Fun", to borrow a phrase from electronic cookbook author Don Lancaster. I did it because there was a question on the speedtalk.com forum about the Pertronix Multispark. I asked if anyone had seen a video of the waveform. No replies, so I imagined what it might look like and spent a few weeks on it. The first spark has variable dwell with RPM, just like the standard unit. That's good, but the spark is cut off after 200usec. That's bad. But that's what you have to do if you want multi sparks. The dwell time for the rest of the sparks is set to 250usec, with a 200usec burn time. That's bad. We want a longer dwell time, and a longer burn time. The only way to do that would be to limit the number of mini sparks, and even then, it would be less than if just making a single, long duration spark. All the while you are making crappy sparks, you are stressing the ignition transistor. Of course, you could get a bigger heat sink and better transistor, but the sparks would still be crappy. And look at the flyback voltage. On my standard version, the flyback voltage is over 400v. Here, you can see it decrease with the number of sparks. Thanks for watching. I'm sure I've seen your name somewhere...?

@@jselectronics8215 In some of the Ford classes I used to teach, we went over their repetitive mode which was another name for multi spark. From the factory, vehicles had it to run leaner mixtures at Idle while preventing misfires with the extra sparks. It would shut off around 1,200 RPM's. I used to look at some patterns on a lab scope and saw three sparks until raising the rpm's shut it off. This is cool stuff, thanks for posting this video!