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Author Topic: Bamford Generator Build  (Read 572 times)
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Wasn't sure where to put this,but here looks good.


Below is a short video of my old 3.5 HP SD1 Bamford Diesel,which i now have running very well on old fish and chip oil.Had to advance the injector timing a bit to get it to run well,but that can be done on the fly with these engines--so we just advance the injector timing until we get the least amount of smoke out of the exhaust,while maintaining the correct rpm-->600rpm.

I cant believe how little fuel these engines use.
Noted that it is unloaded ATM,but still-->3 hours and 47 minutes at running speed on one liter of oil  O0 .

I now collect the old chip oil from 3 fish and chip shops around our city,and they pay me(yes,pay me) to take it away,as it would cost them to have the recycler take it for them.

Not only can i use the oil to run my engine,but i also get $2.00 for every 20 liter drum of oil i take away for them  O0 .
Two of the three shops are on my way home from work,and one is only a 5 minute drive away,so the $2.00 more than pays for the fuel required to pick up the oil.
I get 2 drums(40 liters) from each shop each week on average.

Next is to save up for a 3kva gen head  ;)

https://www.youtube.com/watch?v=-gPX5SHrKJs


Brad
   
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Well,looking through my workshop,i spotted the old 2kva gen head from the old lister startOmatic i scored some years back from the scrap metal dealer here in town-so why not use this one  O0

The startOmatic box/part was no good--all rusted out,and internal components unsalvageable.
But the generator it self looks ok-just covered in years of dust and dirt.

Now,this is where i need a little help,as i am not very familiar with these old brushed type AC generator.

It is a 4 pole generator(4 coils on the rotor),rated at 2kva 50Hz @ 1500 rpm.
The thicker red and black wires go to the two brushes on the slip rings.
The thinner white and grey wires go to the field windings(im guessing?)
I have removed the earth wire.

Placing the DMM across the red and black wire,and spinning the shaft by hand,i can get 2 odd volts ac across the two wires-->same for the white and grey wires.
So im guessing there is still some residual magnetism left in the rotor cores,and AFAIK,that is what use to fire up the generator when a load was placed on it.

Now,my question is-->is it just a mater of placing the right value cap across the field windings to get this thing to fire up?,or are the field windings the 240vac output,and the rotor windings have to be supplied with a DC current,so as we create a N,S,N,S field on the 4 rotor poles?.

Any help would be great and appreciated
Pics below.


Brad
   
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Ok,so thinking about the generator some more,i get that bad feeling that there needs to be some sort of control system for the amount of current flowing through the field windings.

Im thinking that the red and black wires from the rotor slip rings is the 240vac output,and as more load is placed on the output,more current has to flow through the field windings,so as we do not get a voltage drop in the output as the load on the generator is increased.

Am i on the right track?


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Good morning Brad.

Being a " Lister " man you'd have thought I could help you, however the " StartOmatic " plant is something I'm totally green on.

Does the alternator rotor have both a commutator and slip rings? If the answer is no then your alternator must've been replaced at some point, as the unit was designed to start the engine via a 24 Volt battery.

The Lister StartOmatic system was quite clever for its time. The plant was able to detect when the user needed supply, like switching on a light and would start up and run for the duration, only shutting down when the demand ceased.

Cheers Graham.


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Good morning Brad.

Being a " Lister " man you'd have thought I could help you, however the " StartOmatic " plant is something I'm totally green on.

Does the alternator rotor have both a commutator and slip rings? If the answer is no then your alternator must've been replaced at some point, as the unit was designed to start the engine via a 24 Volt battery.

The Lister StartOmatic system was quite clever for its time. The plant was able to detect when the user needed supply, like switching on a light and would start up and run for the duration, only shutting down when the demand ceased.

Cheers Graham.

Hi Graham

The startOmatic i had was the later model,where the engine had it's own 12 volt starter motor.
The unit came from an old country town hospital near by,and would start when the grid power went out.
Grid power was hooked to a double throw relay in the startOmatic control unit,and when the grid power went out,the relay would also loose power,and would switch over to the startOmatic control unit.
(I think i actually posted pictures of it here on the forum somewhere when i first got it.)

Once the engine started,and power was being produced by the generator,a second relay would disconnect the starter motor.
When the mains power came back on,the first relay would kick back in,and connect the mains power back to the building. Another relay would also fire up,and pull the stop lever on the engine.

The control unit was full of relay banks,capacitors,large resistors,and a toroid transformer--which i think may have been part of the load detecting circuit,and DC supply to the field windings.

Im betting ION will know all about this type of generator  ;)


Brad
   

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Hi Brad.

Well that certainly explains why the rotor doesn't have a commutator, doesn't it?   :)

I'm pretty sure there'll be some information out there about the voltage control system, do you think the AC output was taken from the slip rings?

Cheers Graham.


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Hi Brad.

Well that certainly explains why the rotor doesn't have a commutator, doesn't it?   :)

I'm pretty sure there'll be some information out there about the voltage control system, do you think the AC output was taken from the slip rings?

Cheers Graham.

Yes,i believe that the rotor windings are for the 240vac output,and the field windings are to produce the magnetic field,as the rotor windings ohm out at around 4 ohms,and the field windings ohm out at about 260 ohms,and that is to high to output 8 amps @ 240v--you would need around 2000 volts to get 8 amps over 260 ohms.

So our field windings produce our north and south electromagnetic fields,and the current through these windings would have to increase as the load on the AC output increased,otherwise we would get a voltage drop on the output as we applied heavier loads,as  the generator runs at a constant speed.

So,as far as i can work out,we need to design a circuit that delivers more DC power to the field windings as the load on the AC output increases--i think  :-\


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Hi Brad,

I have worked on many generators over the years.  A good general rule of thumb is that speed generates voltage and torque generates current.  In other words if the engine or other primer mover can maintain the proper speed then the voltage will stay up under a heavier current load.  That is why most modern generators work fine with permanent magnets for the field.  When you get yours up and running at the proper RPM to get the right output frequency then you could use an adjustable power supply to set the field current to give you the proper output voltage.   Once you determine the voltage needed you could then use a fixed power supply for the field current.  You only need a control circuit for the field if the rpm of the generator is changing.  Since the output of an AC generator has to be close to the required AC frequency then the field does not need to be controlled.  I hope this helps some.

Sorry to see you gone from OU.com

Take care,
Carroll


---------------------------
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The old Bamford is quite a machine.  Lovely sound as it runs!

Could it be that your Gen Head has two sections:

(1) the DC exciter generator to provide field current

(2) the Alternator Coils to provide the AC output?

It should be possible to make a Solid State Regulator
to control Field Current to stabilize the output AC
under varying loads.  Unless, of course, it would be
preferred to use the old relay regulator circuitry of
the time.

You have some of the most interesting projects
I've ever seen.  Working with the Old Stuff is
always challenging but extremely rewarding.


---------------------------
"Truth: the most deadly weapon ever discovered by humanity. Capable of destroying entire perceptual sets, cultures, and realities. Outlawed by all governments everywhere. Possession is normally punishable by death." - John Gilmore (1935- ) Author
   
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Hi Brad,

I have worked on many generators over the years.  A good general rule of thumb is that speed generates voltage and torque generates current.  In other words if the engine or other primer mover can maintain the proper speed then the voltage will stay up under a heavier current load.  That is why most modern generators work fine with permanent magnets for the field.  When you get yours up and running at the proper RPM to get the right output frequency then you could use an adjustable power supply to set the field current to give you the proper output voltage.   Once you determine the voltage needed you could then use a fixed power supply for the field current.  You only need a control circuit for the field if the rpm of the generator is changing.  Since the output of an AC generator has to be close to the required AC frequency then the field does not need to be controlled.  I hope this helps some.



Take care,
Carroll

Hi Carroll

Thanks for the input.

I would have thought that the output voltage would drop as the load increased,regardless of a steady RPM.
If the load resistance decreases,would not the current flow increase?,and if so,wouldnt we dissipate more power through the rotor windings?.

Anyway,i need 1500 RPM at the generator,and the motor runs at 600 RPM--so i need a 2.5:1 gear up.
I will pick up the needed pulleys and belts this week,and put it together. Then we'll just hook up a load and our DC power supply,and start doing some testing.  O0

Quote
Sorry to see you gone from OU.com

Well,when others start removing your posts because they do not agree with the !others! ideas and thought's,it's time to move on.


Brad
   
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The old Bamford is quite a machine.  Lovely sound as it runs!

Could it be that your Gen Head has two sections:

(1) the DC exciter generator to provide field current

(2) the Alternator Coils to provide the AC output?

It should be possible to make a Solid State Regulator
to control Field Current to stabilize the output AC
under varying loads.  Unless, of course, it would be
preferred to use the old relay regulator circuitry of
the time.

You have some of the most interesting projects
I've ever seen.  Working with the Old Stuff is
always challenging but extremely rewarding.

I think most of the old stuff is better than what we have today.
I mean--just look at that motor  :),big,solid,and would outlast the high revving shitboxes we have today.
No complicated electronic ignition systems of fuel systems--just crank and go. O0

Love the old stuff  :D


Brad
   
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It's turtles all the way down
Compounding would help with regulation i.e. a portion of the load output current is added to the  normal field current and this can compensate resistive losses in the copper of the output coils under heavier loads.

https://electricalstudy.sarutech.com/characteristic-of-dc-compound-wound-generators/index.html

If you have an alternator instead of a DC machine, there are also ways to compound.

Regards


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Compounding would help with regulation i.e. a portion of the load output current is added to the  normal field current and this can compensate resistive losses in the copper of the output coils under heavier loads.

https://electricalstudy.sarutech.com/characteristic-of-dc-compound-wound-generators/index.html

If you have an alternator instead of a DC machine, there are also ways to compound.

Regards

Hi ION

The generator is an AC generator.

I know it gets confusing some time's,as we call 240 volt AC alternators generators over here,and AFAIK,it's the same world wide ?.


Brad
   
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... .-.. .. -.. . .-.
Cracking project !
The whole thing running on throw away oil is good enough, but if it can run your fridge as well ? great bonus.
Logic would say that if you load the generator it would drop voltage and current after a point. I wonder if generators ever speed up to cope with a load ? Is there a 'generator shop' that you could visit and inspect how a similar unit works ?

I'd start the thing, connect a meter, add a small load and increase the loading to see what happens and then you'll know what to fix. Actually, no, i'd just connect a light bulb, start the engine and run out of the range of any glass  :D


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Cracking project !
The whole thing running on throw away oil is good enough, but if it can run your fridge as well ? great bonus.
Logic would say that if you load the generator it would drop voltage and current after a point. I wonder if generators ever speed up to cope with a load ? Is there a 'generator shop' that you could visit and inspect how a similar unit works ?

I'd start the thing, connect a meter, add a small load and increase the loading to see what happens and then you'll know what to fix. Actually, no, i'd just connect a light bulb, start the engine and run out of the range of any glass  :D

Yea,love these old motors,and this Bamford would be the most overbuilt 3.5 HP motor i have ever seen-its awsome,and will see me out i recon.

I would expect the voltage to drop and an increase in current flow as the load increases. This is why i believe that the field windings power will have to be increased as the load increases.

Anyway, I'll  get it all mounted up,and run some load tests,and see what happens.

Once up and running,i will then be installing the HV HHO system to get the fuel economy up,and emissions down.


Brad
   
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At the 2008 Free energy conference in Wales, an account was given of a Volvo diesel which had exceptional mileage. The car was taken in for its MOT and when it came back, the mileage dropped to normal. This was disappointing. He looked through the invoice to see if he could spot anything. There was an amount for a replacement temp sensor in the fuel line heater. the heater was running continuously and never switched off.

It looks as if over heating the fuel may have an effect on diesel mpg.
   
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You can also get improved mpg by adding some petrol to the diesel. as I found out when I accidentally put some petrol into my motorhome (RV).  Luckily I stopped before filling the tank, then phoned my nephew who is a motor mechanic.  He advised topping up with proper diesel which I did, and it ran very well with improved mpg.  Didn't continue the practice as prolonged operation could ruin the engine.
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Hi Paul-R.

Having run a 2 Litre Diesel BMW for several years I mentioned to Chet that I noticed a significant drop in MPG over the winter months. It led me to the conclusion that fuel temperature might have a bearing.

A simple idea might be to pass the fuel through a water heated tube, the engine itself providing said heat.

Cheers Graham.


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Hi Paul-R.

Having run a 2 Litre Diesel BMW for several years I mentioned to Chet that I noticed a significant drop in MPG over the winter months. It led me to the conclusion that fuel temperature might have a bearing.

A simple idea might be to pass the fuel through a water heated tube, the engine itself providing said heat.

Cheers Graham.

You will indeed get better MPG if the diesel fuel is heated before it is injected into the engine.
Cold diesel dose not atomise properly inside the combustion chamber--this is what causes diesel knock when you cold start a diesel engine.

Simple test
Throw a lit match into a pot of cold diesel--match will go out
Now throw a lit match into a pot of diesel that has been preheated to 80*C,and see what happens.


Brad
   
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Update

Been a busy week at work.
Been building a new workshop,and splitting the spar parts building into two halves.
The partition wall was 8 meters high x 27 meters long,so was a big job.

Anyway,i picked up the pulley's and belts today,and started machining them out to fit the generator shaft.
The larger 7.5" one that is to be fitted to the motor will need to be bolted on,as not enough shaft left to fit it onto.
So ,a bit tricky,but we should manage it  O0.

Should be all fitted by lunch time tomorrow,and then we can sort out this field supply circuit.


Brad
   
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