Alternator Paralleler Circuit

[Smelly]

Err, could you try that again?

 

cheers,

Pete

 

ｎｏ　ｇｏｏｄ　ａｔ　ｃｉｒｃｕｉｔ　ｄｉａｇｓ　ｓｏ　ｂｅａｒ　ｗｉｔｈ　ｍｅ．．．　Ｅｖｅｎ　ｓｐｅｃｉｆｙｉｎｇ　ａ　ｄｉｆｆｅｒｅｎｔ　ｆｏｎｔ　ｄｏｅｓｎ’ｔ　ｃｈａｎｇｅ　ｔｈｉｎｇｓ　ｅｉｔｈｅｒ．

 

Ｂｅｔｗｅｅｎ　ｔｈｅ　ｐｕｓｈｂｕｔｔｏｎ　ａｎｄ　Ｗ　（ｏｒ　Ｄ　ｎｏｗ）　ｔｈｅｒｅ　ｉｓ　ａｎ　ｉｌｌｕｍｉｎａｔｅｄ　ｓｗｉｔｃｈ，　ｉ　ｓｕｓｐｅｃｔ　ｉｔ’ｓ　ａｎ　ＬＥＤ．　Ｗｈｅｎ　ｃｏｎｎｅｃｔｅｄ　ｔｏ　Ｗ，　ｗｉｔｈ　ｔｈｅ　ｓｗｉｔｃｈ　ｓｗｉｔｃｈｅｄ　ｏｎ　ｔｈｅｎ　ｗｈｅｎ　ｉ　ｐｒｅｓｓ　ｔｈｅ　ｐｕｓｈｂｕｔｔｏｎ　ｔｈｅ　ＬＥＤ　ｉｌｌｕｍｉｎａｔｅｓ　ａｓ　ｉｔ’ｓ　ｏｂｖｉｏｕｓｌｙ　ｆｉｎｄｉｎｇ　ａ　ｐａｔｈ　ｔｏ　ｅａｒｔｈ．　Ｌａｍｐ　ｏｎｅ　ｄｏｅｓ　ｎｏｔｈｉｎｇ　ｗｈｅｎ　ｉ　ｐｕｓｈ　ｔｈｅ　ｂｕｔｔｏｎ．　

 

Ｗｉｔｈ　ａ　ｒａｗ　１２ｖ　ｆｅｅｄ　ｃｏｎｎｅｃｔｅｄ　ｔｏ　ｔｈｅ　ｌａｔｃｈ　ｒｅｌａｙ　ｃｏｉｌ　ｔｈｅｎ　ｗｈｅｎ　ｉ　ｐｒｅｓｓ　ｔｈｅ　ｐｕｓｈ　ｂｕｔｔｏｎ　ｌａｍｐ　１　ｌｉｇｈｔｓ．　　

 

Ｗｉｔｈ　Ｄ　ｃｏｎｎｅｃｔｅｄ　ａｓ　ｏｐｐｏｓｅｄ　ｔｏ　Ｗ　ｎｏｔｈｉｎｇ　ｈａｐｐｅｎｓ．

 

Ｉ　ｓｕｓｐｅｃｔ　ｔｈｅ　ＬＥＤ　ｉｓ　ｉｎ　ｓｅｒｉｅｓ　ｗｉｔｈ　ｔｈｅ　ｌａｔｃｈ　ｒｅｌａｙ　ａｎｄ　ｗｉｌｌ　ａｍｅｎｄ　ｔｈａｔ　ａｎｄ　ｒｅｐｏｒｔ　ｂａｃｋ，　ｈｏｗｅｖｅｒ　ｉｔ’ｓ　ｂａｔｔｅｒｙ　ｃｈａｒｇｉｎｇ　ｔｉｍｅ　ｎｏｗ　ｓｏ　ｔｅｓｔｉｎｇ　ｗｉｌｌ　ｂｅ　ｌｉｍｉｔｅｄ．

[RLWP]

ｎｏ　ｇｏｏｄ　ａｔ　ｃｉｒｃｕｉｔ　ｄｉａｇｓ　ｓｏ　ｂｅａｒ　ｗｉｔｈ　ｍｅ．．．

 

Thank God. I thought he had electrocuted himself!

 

Richard

[smileypete]

ｎｏ　ｇｏｏｄ　ａｔ　ｃｉｒｃｕｉｔ　ｄｉａｇｓ　ｓｏ　ｂｅａｒ　ｗｉｔｈ　ｍｅ．．．　Ｅｖｅｎ　ｓｐｅｃｉｆｙｉｎｇ　ａ　ｄｉｆｆｅｒｅｎｔ　ｆｏｎｔ　ｄｏｅｓｎ’ｔ　ｃｈａｎｇｅ　ｔｈｉｎｇｓ　ｅｉｔｈｅｒ．

 

Ｂｅｔｗｅｅｎ　ｔｈｅ　ｐｕｓｈｂｕｔｔｏｎ　ａｎｄ　Ｗ　（ｏｒ　Ｄ　ｎｏｗ）　ｔｈｅｒｅ　ｉｓ　ａｎ　ｉｌｌｕｍｉｎａｔｅｄ　ｓｗｉｔｃｈ，　ｉ　ｓｕｓｐｅｃｔ　ｉｔ’ｓ　ａｎ　ＬＥＤ．　Ｗｈｅｎ　ｃｏｎｎｅｃｔｅｄ　ｔｏ　Ｗ，　ｗｉｔｈ　ｔｈｅ　ｓｗｉｔｃｈ　ｓｗｉｔｃｈｅｄ　ｏｎ　ｔｈｅｎ　ｗｈｅｎ　ｉ　ｐｒｅｓｓ　ｔｈｅ　ｐｕｓｈｂｕｔｔｏｎ　ｔｈｅ　ＬＥＤ　ｉｌｌｕｍｉｎａｔｅｓ　ａｓ　ｉｔ’ｓ　ｏｂｖｉｏｕｓｌｙ　ｆｉｎｄｉｎｇ　ａ　ｐａｔｈ　ｔｏ　ｅａｒｔｈ．　Ｌａｍｐ　ｏｎｅ　ｄｏｅｓ　ｎｏｔｈｉｎｇ　ｗｈｅｎ　ｉ　ｐｕｓｈ　ｔｈｅ　ｂｕｔｔｏｎ．　

 

Ｗｉｔｈ　ａ　ｒａｗ　１２ｖ　ｆｅｅｄ　ｃｏｎｎｅｃｔｅｄ　ｔｏ　ｔｈｅ　ｌａｔｃｈ　ｒｅｌａｙ　ｃｏｉｌ　ｔｈｅｎ　ｗｈｅｎ　ｉ　ｐｒｅｓｓ　ｔｈｅ　ｐｕｓｈ　ｂｕｔｔｏｎ　ｌａｍｐ　１　ｌｉｇｈｔｓ．　　

 

Ｗｉｔｈ　Ｄ　ｃｏｎｎｅｃｔｅｄ　ａｓ　ｏｐｐｏｓｅｄ　ｔｏ　Ｗ　ｎｏｔｈｉｎｇ　ｈａｐｐｅｎｓ．

 

Ｉ　ｓｕｓｐｅｃｔ　ｔｈｅ　ＬＥＤ　ｉｓ　ｉｎ　ｓｅｒｉｅｓ　ｗｉｔｈ　ｔｈｅ　ｌａｔｃｈ　ｒｅｌａｙ　ａｎｄ　ｗｉｌｌ　ａｍｅｎｄ　ｔｈａｔ　ａｎｄ　ｒｅｐｏｒｔ　ｂａｃｋ，　ｈｏｗｅｖｅｒ　ｉｔ’ｓ　ｂａｔｔｅｒｙ　ｃｈａｒｇｉｎｇ　ｔｉｍｅ　ｎｏｗ　ｓｏ　ｔｅｓｔｉｎｇ　ｗｉｌｌ　ｂｅ　ｌｉｍｉｔｅｄ．

 

I've PM'd my phone no. over to you.

 

Edit:

 

Can anyone else read what he's saying?

 

cheers,

Pete.

Edited May 19, 2009 by smileypete

[Guest]

Thank God. I thought he had electrocuted himself!

 

Richard

 

I've PM'd my phone no. over to you.

 

Edit:

 

Can anyone else read what he's saying?

 

cheers,

Pete.

No. Thought it was my glaucoma again. This is better than watching Hollyoaks.

[Cosmic]

I think he's saying:

 

no good at circuit diags so bear with me... Even specifying a different font doesn’t change things either.

 

Between the pushbutton and W (or D now) there is an illuminated switch, i suspect it’s an LED. When connected to W, with the switch switched on then when i press the pushbutton the LED illuminates as it’s obviously finding a path to earth. Lamp one does nothing when i push the button.

 

With a raw 12v feed connected to the latch relay coil then when i press the push button lamp 1 lights.

 

With D connected as opposed to W nothing happens.

 

I suspect the LED is in series with the latch relay and will amend that and report back, however it’s battery charging time now so testing will be limited.

[Guest]

I think he's saying:

Your eyesight is better than mine.

[Cosmic]

The earlier posts were

 

Post 271:

 

Nothing on lamp 1 when the engine’s running, although interesting to note that the little indicator lamp in the switch i’ve put on before the pushbutton lights up when the push button is pressed, however lamp 2 doesn’t.

 

Post 273:

 

Well, I’ve Just enough time to connect to D on the engine alt so here goes...

 

(his posts seem to be coming out using unicode. I pasted themn into an editor that allows them to be displayed as ANSI)

[smileypete]

The earlier posts were

 

Post 271:

 

Nothing on lamp 1 when the engine’s running, although interesting to note that the little indicator lamp in the switch i’ve put on before the pushbutton lights up when the push button is pressed, however lamp 2 doesn’t.

 

Post 273:

 

Well, I’ve Just enough time to connect to D on the engine alt so here goes...

 

(his posts seem to be coming out using unicode. I pasted themn into an editor that allows them to be displayed as ANSI)

 

Thanks!

 

I spoke to him on the phone too, and asked him to check there is a usable output from W while the engine is running, using a test lamp between W and 0V.

 

With the circuit connected to W and the engine running, there should be something on Lamp 1 while the pushbutton switch is held down.

 

If there is nothing on Lamp 1 with the engine running and while the pushbutton switch is held down, then it's likely there's a break somewhere.

 

So I'll ask him while the engine is running to trace through using the test lamp connected to ground, starting at W, then the other side of the fuse holder, then the end of the relay coil nearest W. In each case the test lamp should light, if not there's a break.

 

Then connect the test lamp to B+ and while the pushbutton is pressed, connect the other end of the test lamp to the end of the relay coil nearest the diode, then either side of the diode connected to the relay coil, then either side of the relay contacts. Again in each case the test lamp should light, if not there's a break.

 

cheers,

Pete.

Edited May 19, 2009 by smileypete

[Smelly]

Right, on the other PC now...

 

With W connected there is 7.2 volts at the live side of the latch relay coil. With D connected there's 14.3 at the same terminal.

 

With D connected, when I push the push button, the LED in the switch in series with the coil/pushbutton lights up but the relay doesn't latch. With W connected the LED isn't as bright.

 

I've tried the test lamp across coil +ve to switched -ve and it didn't light, but that merits running again as the connection was hastily done with my test lead in parallel, I'll need to solder a new test lamp together and re-connect to W.

 

The essential question which I'm sure one of you can answer is why the latch relay isn't closing, either with W or D connected, when with a raw 12V lead to the coil +ve it works.

 

I'm giving up now.

 

edited coz Gibbo spotted the obvious mistake.

 

I won't be doing much tomorrow as I've got a training course to present on Thursday and need to swot up, however if anyone can come up with a convincing fix, other than try Pete's plan B then I'll try.

 

I've not connected the diode across the latch relay coil, might that crack it? Sorry I forgot.

 

Dan

Edited May 20, 2009 by Smelly

[Timleech]

Funnily enough, even before you wrote this, I did just that and took a scope up to the boat this morning and also had a good look through my star/delta file on board which contains all the data from that experiment of a few months ago.

 

I owe you and Gibbo an apology as you are quite right. The W connection is indeed about 2v above the B+ connection.

 

The voltages to which I was referring yesterday and before (eg: 60v peak to peak), I now realise are the internal voltages generated within the stator windings in order to be able to drive the charge current through the battery.

 

These voltages are not accesible to the outside world (unless the alternator is open-circuited) because of the voltage drop across the stator windings. This is analogous to an actual battery voltage not being accessible to the real world (unless the battery is open-circuited) because any currents drawn off cause a voltage drop across its internal resistance.

 

So, if the charge current is say 50A, the battery to be charged is at 12.4v say and the stator windings have a resistance of 0.3 ohms, then the internally generated alternator voltage is 12.4v + 2v + 0.3Rx50A = 29.4v peak (58v peak to peak or 21v rms).

 

 

So apologies again for my dogmatic, but incorrect, view which clearly shows that Saga moments are for real.

 

Chris

 

So you're saying the voltages to which you referred don't actually exist, they're just computed to fit in with circuit analysis?

 

Tim

[smileypete]

The essential question which I'm sure one of you can answer is why the latch relay isn't closing, either with W or D connected, when with a raw 12V lead to the coil +ve it works.

 

Smelly,

 

Do you have Lamp 1 connected across the latch relay coil exactly as per the diagram in post #168?

 

And with the latch relay feed connected to 12V, does Lamp 1 light while the push button switch is pressed?

 

And with the latch relay feed is connected to W while the engine is running, does Lamp 1 light up at all while the push button switch is pressed?

 

cheers,

Pete.

Edited May 19, 2009 by smileypete

[Smelly]

When it's connected to W or D, was this with the engine running, and when the pushbutton switch is pressed?

 

Did Lamp 1 across the latch relay coil light up at all?

 

In either case Lamp 1 should light up at the very least.

 

If there's nothing getting to Lamp 1 then there's a break somewhere, and doing other things won't help.

 

cheers.

Pete.

 

Lamp 1's not lighting at all connected to D which i agree is wierd as it's in parallel to the pushbutton which, when it's pushed, runs straight to 0v, not a semiconductor in sight.

[smileypete]

Lamp 1's not lighting at all connected to D which i agree is wierd as it's in parallel to the pushbutton which, when it's pushed, runs straight to 0v, not a semiconductor in sight.

 

OK

 

Do you have Lamp 1, which must be a normal lamp of about 1W, connected across the latch relay coil exactly as per the diagram in post #168?

 

And with the latch relay feed connected to 12V, does Lamp 1 light while the push button switch is pressed?

 

And with the latch relay feed is connected to W (not D) while the engine is running, does Lamp 1 light up at all while the push button switch is pressed?

 

cheers,

Pete

Edited May 19, 2009 by smileypete

[Smelly]

OK

 

Do you have Lamp 1, which must be a normal lamp of about 1W, connected across the latch relay coil exactly as per the diagram in post #168?

 

And with the latch relay feed connected to 12V, does Lamp 1 light while the push button switch is pressed?

 

And with the latch relay feed is connected to W (not D) while the engine is running, does Lamp 1 light up at all while the push button switch is pressed?

 

cheers,

Pete

 

Right lamp 1 is parallel to the latch relay coil...

 

With 12v across the coil lamp one lights when the push button is pressed, and stays lit once unpressed, until the connection to live is broken.

 

With the D connected lamp 1 doesn't light. I can't reconnect to W yet as I've not got the connectors. D's the warning light isn't it?

 

I'm getting superstitious about using W as , not only did Gibbo say above that a lot of fitters need to use lower voltage relays which will be difficult to obtain in the timescales i envisage doing this, but a PM from a concerned bystander said the same.

 

Sticking with D... why isn't the latch relay closing?

[smileypete]

Right lamp 1 is parallel to the latch relay coil...

 

With 12v across the coil lamp one lights when the push button is pressed, and stays lit once unpressed, until the connection to live is broken.

 

With the D connected lamp 1 doesn't light. I can't reconnect to W yet as I've not got the connectors. D's the warning light isn't it?

 

I'm getting superstitious about using W as , not only did Gibbo say above that a lot of fitters need to use lower voltage relays which will be difficult to obtain in the timescales i envisage doing this, but a PM from a concerned bystander said the same.

 

Sticking with D... why isn't the latch relay closing?

Smelly,

 

I'm very very sorry, but I really do have to stop with this from now. Mea Culpa.

 

I'm sure Gibbo and/or Chris W can help you from here.

 

If it doesn't work from W then there should be a simple work-around for using W that doesn't involve getting another relay.

 

Or alternatively there is the simplified circuit I posted.

 

In either case Gibbo and Chris W should know what to do.

 

You've done brilliantly well so far, and deserve a lot of kudos for getting it to where it is. Thanks for sticking with it so far.

 

cheers,

Pete.

[chris w]

So you're saying the voltages to which you referred don't actually exist, they're just computed to fit in with circuit analysis?

 

Tim

The voltages DO exist but, as in my analogy to a normal battery above, they are not accessible. For example, let's say, on a normal battery, you have it delivering 20A to a load. You measure the voltage across the load as 12.2v.

 

But what is the actual battery voltage? It's not 12.2v because the current has to pass through the battery's own (inaccesible to humans) internal resistance. If that resistance is say 20 millohms (mR), then 20A through 20mR is 0.4v. So the true battery voltage is 12.2v +0.4v = 12.6v. That is a real voltage but is not accessible to measuring instruments. But it is this real voltage, which is determined by the rpm of the alternator and the rotor current, which determines what charge current is produced.

 

Chris

Edited May 19, 2009 by chris w

[carlt]

It's a bit like god, it's no use to anyone, can't be detected but it gives chris some comfort.

[chris w]

Smelly

 

I believe the reason that the W connection doesn't work is because the voltage at that point is a square wave with a frequency of about 200Hz at idle (and even higher at higher revs). That means that the W connection is only up at 16v or so for 2.5 millisecsonds (and even less at higher revs) before plunging down to virtually zero volts for 2.5 milliseconds and then back up to 16v and so on, ad infinitum. The liitle indicator lamp is lighting up because it can react fast enough to the switching frequency of the W connection, but the relay cannot.

 

I believe you will have to end up connecting the + side of the relay to the ignition 12v and the negative side of the relay, through a diode, to the field connection of the regulator. This is not something that I believe you would be comfortable in doing yourself as it can be a bit tricky without reasonable electrical knowledge, eg, because some field connections are stainless steel a special flux is needed to solder a wire to it. Which alternator do you have as I may be able to talk you through it. Can you PM me a photo of your alternator?

 

My circuit works perfectly but did involve getting into the field connection.

 

Chris

[Gibbo]

Smelly I'm assuming you're working from the diagram in post #168?

 

If so, I don't think you have included the diode at top left in between the picture of lamp 1 and the latch relay.

 

If you add that diode it will probably work from the W terminal.

 

Gibbo

[Smelly]

Smelly I'm assuming you're working from the diagram in post #168?

 

If so, I don't think you have included the diode at top left in between the picture of lamp 1 and the latch relay.

 

If you add that diode it will probably work from the W terminal.

 

Gibbo

 

My hot question is why it's no working from D.... but cheers guys!

 

The money faerie has arrived so I can buy the connectors to connect back to W, but don't plan to as I might need to obtain a latching relay that works at a lower voltage which will take too long... I want it DONE!

 

I will add the diode, which admittedly I've failed to do, and go from there. But I'm still baffled as to why it doesn't work from D??

 

Pete don't worry, we're experimenting; this is what it's all about, plus an excuse for a cooling off pint is no bad thing

 

Gibbo, I am working from 168, and in my last post stripped it back and tested all the connections, i felt quite swanky typing results in as I tested However the lamp 1 diode isn't there... Yet!

 

Why can't I use D... in words of less than 2 para's with no-one falling out please...

 

Chris, one final ask... i am prepared to go into the field connection iF either Pete's second circuit doesn't work (will it switch off?) or I run out of patience, however i would like a spare reg in the background. I don't sUPpose you've a part number? I've an Isuzu 35 with twin Prestolite analogues, we've boats of a similar age so I think we've prob got the same alt's.

Edited May 19, 2009 by Smelly

[Smelly]

I believe you will have to end up connecting the + side of the relay to the ignition 12v and the negative side of the relay, through a diode, to the field connection of the regulator. This is not something that I believe you would be comfortable in doing yourself as it can be a bit tricky without reasonable electrical knowledge, eg, because some field connections are stainless steel a special flux is needed to solder a wire to it. Which alternator do you have as I may be able to talk you through it. Can you PM me a photo of your alternator?

 

Chris

 

I will PM if needs be, but would rather stick to a circuit outside (although see my last post). I've thought about going back to the egg timer we discussed many moons ago but would rather not.

 

Thank you.

 

Thursday afternoon is the deadline as i'll finish at three so can have another good run up.

 

If we can make this work in a relatively end user way then we've done a good thing and saved not only me but any sensible boaters loads of cash and carbon... I'm in it til it sets the boat alight... one way or the other!

[chris w]

Chris, one final ask... i am prepared to go into the field connection iF either Pete's second circuit doesn't work (will it switch off?) or I run out of patience, however i would like a spare reg in the background. I don't sUPpose you've a part number? I've an Isuzu 35 with twin Prestolite analogues, we've boats of a similar age so I think we've prob got the same alt's.

That's great.... we both have Prestolites, which are actually Lucas A127 look-a-likes and use the same regulator. You can get them very cheaply (a tenner) from Ebay. If you send it to me I will modify it for you and solder on the extra wires needed.

 

I have PM'd you some additional stuff too.

 

Chris

[chris w]

Why can't I use D... in words of less than 2 para's with no-one falling out please...

have you checked the voltage you are getting on D+ with a multimeter?

 

Chris

[Smelly]

That PM's not landed yet however I will thank you in advance.

 

A suggestion of a 1000u/f capacitor to ground from the latching relay has been made. I'd like a way of switching it separately from the ignition although that can be arranged. Plus I've great big holes in the control stand now that might as well do something!

 

I still don't trust W, but again I have advice that D won't switch off. Seems reasonable considering what has been posted above.

 

Chris, just assuming (save me getting my camera out at this time of night) we've the same regs, were they SS springs, or was it something a not quite novice soldered could achieve? Special flux etc not being needed! Come Friday I will happily pick up a spare reg and will photo it tomorrow if I remember but in the meantime a hint would be nice. I am reluctant to take the existing reg off without a replacement as we live aboard with no hookup so it's an important bit of kit. When I asked someone to mod it for the Sterling (and having used underspec cable I ended up doing it myself anyway) the jump lead from bank to bank drill was onerous to say the least. ( and I ended up re-doing it )

 

If the diode across the latching relay doesn't work I'm probably going to switch the latching relay for the time being, just so I can see a result... if it does then Pete was right all along and I'll apologise for wasting everyone's time!

 

Finally, the combi meter was a duffer, it's doing all sort of unusual things. I'll order another one in June but next month it's either car or woodwork that's going to eat my cash... I'd prefer woodwork as that tends to work without too many complaints

[chris w]

That PM's not landed yet however I will thank you in advance.

 

A suggestion of a 1000u/f capacitor to ground from the latching relay has been made. I'd like a way of switching it separately from the ignition although that can be arranged. Plus I've great big holes in the control stand now that might as well do something!

I don't think that will work.

 

I still don't trust W, but again I have advice that D won't switch off. Seems reasonable considering what has been posted above.

D+ won't switch off, but have you checked the volts on it with your multimeter?

 

Chris, just assuming (save me getting my camera out at this time of night) we've the same regs, were they SS springs, or was it something a not quite novice soldered could achieve? Special flux etc not being needed!

Some spare reg brush holders will solder with any normal solder but some are SS. With the latter you need to use plumber's flux (B&Q) and dab that on generously and then use plumbers solder (ie: just plain solder with no multicore flux in it. It works a treat.

 

Chris