1972 electric shift

[johnb]

Re: 1972 electric shift

Wow! A lot of responses.

Here is another one for ya. This fella salvages Johnson motors and has quite a supply of salvaged materials. You might want to send him an e-mail for a quote:

http://www.laingsoutboards.com/

 

[samo_ott]

Re: 1972 electric shift

Interestingly enough, I've dabled in electronics my whole life and also thought the diode pic was reversed. I always thought current flowed against the arrow. So I looked it up also. There's a good pic and explanation here:

massmind.org/images/www/hobby_elec/e_diode.htm

You learn something every day!

 

[F_R]

Re: 1972 electric shift

Interestingly enough, I've dabled in electronics my whole life and also thought the diode pic was reversed. I always thought current flowed against the arrow. So I looked it up also. There's a good pic and explanation here:

massmind.org/images/www/hobby_elec/e_diode.htm

You learn something every day!

Now un-learn it!!

You were correct--current flows against the arrow. The referenced link is wrong. The confusion comes from the fact that most people think current (flow of electrons) is from positive to negative. Not so. It is from negative to positive. I had a terrible time with that lesson in TV repair school.

Also just for the record when trying to understand diodes as related to alternators, charging current flows BACKWARDS through the battery (in the + and out the -). EDIT: dagnabbit, now I got it reversed. Charging current flow is in the - and out the +. Backwards of discharge flow.

 

[jameskb2]

Re: 1972 electric shift

Now un-learn it!!

You were correct--current flows against the arrow. The referenced link is wrong. The confusion comes from the fact that most people think current (flow of electrons) is from positive to negative. Not so. It is from negative to positive. I had a terrible time with that lesson in TV repair school.

Also just for the record when trying to understand diodes as related to alternators, charging current flows BACKWARDS through the battery (in the + and out the -).

Huh, it appears I might be the one that got learned. I always thought current flowed in the arrow's direction, and used that direction to orient the stripe, which is right in application, but wrong in the fact that negative to positive is the electron's flow direction.


HERE (link) it's explained.

"Oddly enough, the direction of the diode symbol's “arrowhead” points against the direction of electron flow. This is because the diode symbol was invented by engineers, who predominantly use conventional flow notation in their schematics, showing current as a flow of charge from the positive (+) side of the voltage source to the negative (-). This convention holds true for all semiconductor symbols possessing “arrowheads:” the arrow points in the permitted direction of conventional flow, and against the permitted direction of electron flow."

What's confusing to me, is that the installation of the actual diode, for the circuit to work AS INTENDED, is correct if you use the symbol's orientation. The cathode should face the shift diode's feed, not the ignition switch. So, the factory diagram is correct. No?

Crap, now I'm confused. I've always installed the cathode (stripe side) to block current flow, and that's the way the schematic shows it, but the technical facts are that the electrons flow differently.

So, there it is. Engineers, and electrons are not conventional. I wonder if they have piercings and purple spiked mohawks.

Sorry about that!

Although, it appears that current flow, and electron flow, are two different things? Hmmm.... Somehow, somewhere, we got wires crossed.

Edit: Ok, I get it now. The link above is right, IF negative to positive is flow. Since we are blocking the positive side in the shift diode circuit, it's shown correctly. I understand now that negative flows to positive, that engineer's that designed the symbols used a positive to negative bias for their flow direction making the symbol "backwards" in truth, but not in application. The arrow should always point from negative (ground) to positive to block a positive charged lead. It's the polarity of the circuit that determines the orientation of the diode and it's corresponding symbol. So the symbol in the factory schematic is correctly oriented.

Edit 2: Thanks F_R, for the lesson!

 

[samo_ott]

Re: 1972 electric shift

Ah man... now I'm really confused Must be time for a beer!

 

[F_R]

Re: 1972 electric shift

Here's the current flow for the shift circuit, key on, neutral selected. Ignoring the feed from the alternator.
http://i155.photobucket.com/albums/s311/frankr_photos/Wiring197285hpShiftflow.jpg?t=1206582108

Challenge: can anybody figure out the alternator supply to the shift?

 

[jay_merrill]

Re: 1972 electric shift

LOL! See, I'm not so crazy for trying to go through this step by step! Most of us are not specifically trained in all of this, so the participation by everyone is valuable in that we are all learning about these motors. That is exactly why I have spent so much time in IBoats during the few moths since I found the forum. Call me a knowledge junkie if you like - I just enjoy it.

 

[jameskb2]

Re: 1972 electric shift

Challenge: can anybody figure out the alternator supply to the shift?

Yes.

Using your diagram, the electrons flow from the solenoids (engine ground, battery negative) along the leads from them to the shift switch and through that switch when closed. It travels then along the shift switch diode wire to the diode itself, which is connected to the stator and rectifier wires. Then along the rectifier wires to the rectifier, through the rectifier's internal diodes, and then along the positive battery lead out of the rectifier. The final leg is that positive lead from the rectifier to the battery.

I think.

Edit: Second possible way. Since you clued us that the charging system flow is actually pos to neg, not neg to pos as in discharge, and the shift diode supplies power from the stator, (12v?) then I think the current might end at the diode? I think that's it. I just read up on rectification and it appears that the shift diode, fed from the stator, is a dual, half wave rectifier. The pos flow from that wire, joined to those two diodes, meets the neg flow from the shift solenoids, completing the circuit. The shift diodes act as the "battery" supplying the pos at that point. I don't know the diode's structure or orientation in the shift diode connected to the stator, so I can't tell if it's full wave, half wave, or if I'm way off completely.

Again, I think.....

 

[F_R]

Re: 1972 electric shift

Here is the charging circuit and alternator supply to the shift switch circuit. Showing only 1/2 of the sine wave. Reverse the alternator polarity and flow direction and use the appropriate diodes for the other half.

http://i155.photobucket.com/albums/s311/frankr_photos/Wiring1972ChargingCircuit.jpg?t=1206624410

http://i155.photobucket.com/albums/...ing1972AlternatorShiftSupply.jpg?t=1206624704

Enjoy

 

[jim kinser]

Re: 1972 electric shift

Thanks for all the info here. A little more than I expected. But I found out what I needed to know. Thanks again.

 

[jameskb2]

Re: 1972 electric shift

Ahhh....

Well, I guess I missed that one! C- on the grade. Got it about half right, half the time! :redface:

Well, I certainly learned something. Thanks so much for explaining that to me. I don't mind being schooled! I struggled with the charge / discharge theme, couldn't figure out where to start. The AC stator...totally missed it.

It's good information for sure. I think I'll be keeping this in the archives as a reference. It'll help me troubleshoot more than just an outboard engine's charging and wiring schemes for sure.

I just got in from work....wondered all day about this.

Thanks again Frank!

James K

 

[JustMrWill]

Re: 1972 electric shift

I went with a 3-way light toggle switch on the dash as a temp fix. I sent my broken switch and a copy of the wiring diagrams to an electrical engineer friend who has a machine shop in his house. He said he can make me a replacement switch. If it works out, maybe he would be willing to make a few to sell. Shoot me a PM and I will get back to you if/when I get one.

-JMW

 

[jay_merrill]

Re: 1972 electric shift

No grades here. I think that about 99% of the time folks learn absoltely nothing more than what they have to in order to solve an immediate problem. The only trouble with that view of life is that, had we done the same, we would not have figured out a way no create a lock-out for the starter circuit, and we would have missed the blocking diode between the shift diode circuit and the battery/rectifier circuit.

By creating a lengthy discussion, we put a bunch of heads together and came up with a solution that just might work for a lot of people. I think we all helped one another develop a better understanding of the electrical system in the early 70s hydroelectric motors too.

 

[jameskb2]

Re: 1972 electric shift

No grades here. I think that about 99% of the time folks learn absoltely nothing more than what they have to in order to solve an immediate problem. The only trouble with that view of life is that, had we done the same, we would not have figured out a way no create a lock-out for the starter circuit, and we would have missed the blocking diode between the shift diode circuit and the battery/rectifier circuit.

By creating a lengthy discussion, we put a bunch of heads together and came up with a solution that just might work for a lot of people. I think we all helped one another develop a better understanding of the electrical system in the early 70s hydroelectric motors too.

I agree Jay!

I defer credit to those more knowledgeable than myself. I have to admit I was overconfident in my ability with this, and what I "thought" was right.

Thanks to both you and Frank (F_R) for your ideas and commitment to the truth and solutions to our application.

I guess, if there was "one more thing" and if F_R has the patience for it, I would request a diode spec on the circuits. What volt / amp rating for them (minimum or maximum or both if required) so that I don't install the wrong ones. I thought I had that figured out too, but after my rose colored glasses came off, I'd rather be safe than sorry.

 

[wavrider]

Re: 1972 electric shift

Now un-learn it!!

You were correct--current flows against the arrow. The referenced link is wrong. The confusion comes from the fact that most people think current (flow of electrons) is from positive to negative. Not so. It is from negative to positive. I had a terrible time with that lesson in TV repair school.

Also just for the record when trying to understand diodes as related to alternators, charging current flows BACKWARDS through the battery (in the + and out the -). EDIT: dagnabbit, now I got it reversed. Charging current flow is in the - and out the +. Backwards of discharge flow.

WOW, so for over 23 years in advanced electronics, weapon guidance systems, infra red communications and navigational systems repair, research and development, more than three years advanced electronics instructor with a Master teaching Specialist certification and curriculum development. I was wrong.

Current flows in the direction of the arrow. That is why you have a Peak Inverse rating PIV, Look at how a Zener diode works,

Outside of a power source (IE battery) current flows from Positive to negative, Inside the battery it flows from Negative to Positive, Use your ammeter to verify.

Transistor theory, is just a P-N junction, same as a diode basically, it uses volatge to bias and turn the junction on etc etc, only in the flow of electrons in the direction of the arrow.

I like this discussions man some of the debates we used to have about trons.

Not really disagreeing with you FR, but if you charge an electric cap, would it discharge if you touched it to a positive reference, or would it discharge if you touched it to ground or a less negative reference? Current flow is current flow. Positive to negative outside a power source

 

[F_R]

Re: 1972 electric shift

James, I don't know the specs of the factory diodes, but overkill is better than underkill. I'm almost afraid to answer after the last post. But I'd use one rated at at least 50 volts and maybe 20 amps.

Wavrider, I'm not going to argue the point or challenge your qualifications, but I was taught what I shared. I also received training on transistors and zener diodes, and what I was taught makes sense. Maybe electricity has changed since then. That's my story and I'm sticking with it.

 

[wavrider]

Re: 1972 electric shift

No worries FR
When I first went through the training they taught Tube theory, and then had to go back through for digital theory and it was a whole new ball game as the flow was very different with the discrete components versus the pentodes, tetrodes and triodes.

Just enjoying the conversations and definately no ego involved.

when I retired 90% of the trouble shooting was done by computers, and what ever the screen called out is what the technician would replace, they never broke out the dvm, or in my case the simpson 260 and verified what the computer program called out, the days of the oscope, dvm, and signal generator injection trouble shooting are about gone, just a few old relics left around (like me) that have to find out why it went bad

Definately enjoying this thread, thanks for reply

FR you are correct, had to refresh my memory,(old n slow) current does flow from P to N until the inverse voltage is reached (inside the junction), usually .6 or .7 volts, has to do with the doping of the P-N junction and the negative holes, electron valiances, so yes it does flow from Positive to negative within the junction, once the diode is forward biased and the n holes are positively charged then the diode forward biases and allows current flow from the N side to the P side.

Thanks for making me think, miss the trons

 

[F_R]

Re: 1972 electric shift

My training was basically vacuum tubes also. Transistors were the new thing. I'm just an old obsolete fart.

I can't stand it. I gotta comment on the capacitor statement. Anybody that knows anything about capacitors knows that they can be charged negatively or positively. And once it is charged, one end holds a positive potential and the other end is negative. So, discharging it is simply a matter of opposite charges attract.

 

[wavrider]

Re: 1972 electric shift

the cap
You are correct

if the cap is charged positive, you can connect the neg side to ground all day and it will stay charged, until it is discharged by connecting the positive side to a ground

in order to charge that cap it would have to have been connected to a negative. by just connecting a positive to the positive side of the cap and no negative it would not charge

you can take two electrolitic caps, connect positive to negative of the two caps and use as an a/c starter cap for a motor, had to do this for my old water pump just to keep it going until i could get a new starter cap..

I remembr arguing (unsuccessfully) with one of my instructors on forward biasing a pn junction in a transistor with negative voltages on both sides, he tried to tell me that as long as one negative voltage was greater than the other negative voltage it would forward bias, maybe in theory but sure as heck not in application. I missed that question on a test, then I built the circuit in the exam and asked him to show me it forward biased, it dont work but in theory it does, Trons are crazy.

 

[F_R]

Re: 1972 electric shift

"Quote: "if the cap is charged positive, you can connect the neg side to ground all day and it will stay charged, until it is discharged by connecting the positive side to a ground

in order to charge that cap it would have to have been connected to a negative. by just connecting a positive to the positive side of the cap and no negative it would not charge" Unquote.

Naturally. Sounds like we are discussing something that we both agree on. Both ends have to be connected to a voltage potential to charge it. Likewise, both ends have to be connected to something to discharge it. The key phrase here is "with respect to". There are all sorts of voltages in a piece of electronic equipment. Even positive and negative at the same part. It all means nothing except when measured "with respect to".