Would this be of value?

[tlynch]

Re: Would this be of value?

First of all - I want one! I most likely would pay up to $45 US.<br /><br />Would is be far cheaper to make something that goes inline between the plug and the spark plug wire that has a light on it? You would buy one for each cylinder and take the wires off, put one of these onto each plug, and then plug the wire back on. You would just run the engine without its cover and you would see these light blinking on your engine. These things would be the size of a sparkplug and cost $2.50 each.<br /><br />By the way, does the "Spark Plug Indicator" that Paddling had do anything different that a timing light?<br /><br />Just my thoughts.<br /><br />Todd

 

[petryshyn]

Re: Would this be of value?

Hi Todd Lynch <br /><br />The system in developement won't require any disconnecting of plug wires. It will check ignition with everything in its original place. How many times I've removed wires and plugs, only to find that it works when you put it back together. What did I fix? Maybe the wire wasn't pushed on all the way and when I reinstalled it, its fixed. If the system is giving trouble, I want to check it before I change anything so that I can prove the fault. <br />This system will sense plug voltage through induction. It will also be hand held and have long 'Plug sensor' wires so that I can monitor the ignition while driving(one man diagnosis)<br />I know of the inline testers you are referring to, but they require an intrusive connection and would be hard to see while driving. (especially on OB with rear heads)<br /><br />The main difference between this and a timing light is that a timing light cannot illustrate the difference between a high or medium or low voltage. Hopefully this unit will give a visual difference.<br /><br />Many misfires occur at high engine speed. Thats where this will shine.<br /><br />Thanks for the interest. I'm waiting on a special neon bulb to experiment with.......<br /><br />

 

[bruoff]

Re: Would this be of value?

Looks verrrry interesting. I really like the<br />non-invasive approach!

 

[CFO94]

Re: Would this be of value?

Remember me? Inboard head scratcher? still waiting to see if they'll refund our money.<br /><br />I'm in for one of your new toys. New gadgets that really work are my favorite.

 

[clanton]

Re: Would this be of value?

CFO94 is the engine running?

 

[EQCM2B]

Re: Would this be of value?

Looks like a good idea to me. I like the idea that you attach it to the wires without disconnecting anything and that it is a one man operation because the wife doesn't help me work on the boat. I'd buy one.

 

[Dennis4b]

Re: Would this be of value?

A friend and I thought about making something like this after suffering from wet plugs a few times.<br /><br />Basically 3 rows of 4 LED's somewhere on the head, green means cilinder is sparking properly, yellow means something is wrong (either wet plug or cable not connected properly) and red means no power detected at all (distributer/coil problem).<br /><br />Would really speed up troubleshooting in those annoying cases where you really don't want to take the cover off in the dark in waves etc <br /><br />For electronics people out there, it'd be a PIC with A/D pins, resistor based voltage divider (assuming this works with the high spark voltages) to keep end voltage between 0 and 5V, (scale down 50.000V to 0v to 5 and 0) and then diagnose accordingly. I need to know what kind of voltage the coil outputs first though, and what the difference between good spark and wet plug looks like. The PIC would also count the sparks, giving you free digital RPM and also a good way to detect mis-firing and light another LED if something is fishy. Cost price for such a thing would be like $10­$15, but I'd spend up to $50 on a ready unit just to save the time.

 

[petryshyn]

Re: Would this be of value?

Hi Dennis4b: THANKS for the interest!!<br /> The ugly thing about using any solid state is:<br />>if the inductive pickup is ever exposed to a direct arc.........game over. I know someone would pull a plug wire off the plug from habit, giving us a possible 50KV down the ole' sense line. PIC=SMOKE....LOL<br />>the polarity of the secondary varies from manufacturer to model which would require additional considerations.<br />>I've been toying with LED's and neon bulbs. >I don't want any external voltage supply or even batteries.<br />>Got some neons coming that look promising.<br />>Got to keep this thing cost effective(cheap cheap cheap), maintenance free and bullet-proof.<br /><br />Thanks<br />

 

[Dennis4b]

Re: Would this be of value?

Schematic, zeners are your friend, so are caps, current limiting resistors, diodes, and the people on various PIC/EE mailinglists who know how to protect PIC's against various abuses (including direct ignition voltages!).<br /><br />You should be able to rectify the result to negate any polarity difference between different coils. <br /><br />I can't speak for other people, but I've sure wished I had something like this already installed! Even if you have never had ignition/plugs related problems, it is nice to be able to just glance at the panel and *know* this is at least working properly!

 

[Dennis4b]

Re: Would this be of value?

By the way, at first glance I though you had built something like this and were interested in selling it Schematic, sorry! <br /><br />For your case the light-based approach sounds good, just use the inductive voltages to light up a neon bulb or whatever. Or something a little more tricky, use a voltage comparison circuit (should be easy) to light one out of three LEDs depending on the voltage level. No need for a PIC in that case, so also no need for an external powesource. However most likely the circuit will need a reference voltage to compare anything against, so there's a small challenge hidden there <br /><br />I want to build it as a permanent panel, it helps diagnosing starting as well as running problems. The reason I would use the PIC is because I already have it do a bunch of other things at the same time! (measure voltage+charging for all batteries, measure RPM's, measure water and air temperatures, measure engine cooling water temperature, measure fuel flow, etc etc)<br /><br />It sounds like you are already coming along nicely though. What are the inductive voltages you can pick up from the ignition cables? Do you know how much they vary across different engines? <br /><br />Keep us posted on the progress! I will do the same

 

[petryshyn]

Re: Would this be of value?

Hi Dennis4b:<br /><br />I realize that zeners, caps, resistor bridges, free-wheeling diodes all provide some level of protection. But.......if the ground lead to the unit is pulled off or pops off by accident, all protection is lost. We're talking 50KV. Under certain conditions, that'll present an arc around 2". In an ideal installation, that wouldn't be a problem,(fixed grounds) but when you have a Tech hanging over the edge of a transom trying to hook this thing up, you got to expect the worst. Heck, if it don't end up in a prop now and then, I'll be surprised!!....LOL<br />

 

[petryshyn]

Re: Would this be of value?

Dennis4b:<br />we kinda got out of phase with our posting...<br /><br />>The voltage picked up will vary substantialy because of the different ign systems out there. Conventional, Mag and CDI all supply a different range of available voltage. I plan on having an on board variable ground which should help to reduce skewing.<br />>Never did get a chance to play with PIC's, but if time permits......always wanted to build a better bread maker that would take feed-back on dough rise and allow for the different variables associated.....LOL...the perfect loaf!!<br /><br />Hey !!! keep us posted on your project...sounds neat! And hang around. Always good to have Electronics expertise at our disposal!!!<br /><br />