ghostlymoron
Well-Known Member
I am struggling to understand the little silver box that controls the voltage apparently. There are six wires connected to it. What are they all for and how does the box work?
Voltage regulator
- Thread starter ghostlymoron
- Start date
VicS
Well-Known Member
whats this ?
The control box for the Dynastart ?
Got some info somewhere if that what it is.
IIRC modern replacements are different to the originals with regulator and solenoid separated instead of both being in the same assembly. I suspect too that the modern regulators are "solid state" rather than electromechanical.
Last edited:
ghostlymoron
Well-Known Member
Yes dynastart again. I've got a silver box which I think is the regulator and a black one that I guess is a relay.
VicS
Well-Known Member
and do you have a control panel with a "start" button, a start/charge switch and a warning light
pvb
Well-Known Member
There are lots of different versions, can you post some pics of the silver box and the black box?
pvb
Well-Known Member
There are lots of different versions, can you post some pics of the silver box and the black box?
ghostlymoron
Well-Known Member
Sorry to be a bit tardy in supplying additional info. The attached photo shows the silver box 'Bosch', the black box to the left and the VSR below.
Vic, I have a silver control panel with push starter, key switch, accessories pull switch, oil warning light and ignition warning light. Haven't got a picture of it (that I can find).
Vic, I have a silver control panel with push starter, key switch, accessories pull switch, oil warning light and ignition warning light. Haven't got a picture of it (that I can find).
VicS
Well-Known Member
Sorry I dont think I can help.
I found the stuff I had but it was all about connecting a new type of regulator, with only 3 connections + earth, and a separate relay in place of a original control box with 5 connections + earth.
I found the stuff I had but it was all about connecting a new type of regulator, with only 3 connections + earth, and a separate relay in place of a original control box with 5 connections + earth.
William_H
Well-Known Member
It may be of some interest if I describe the regulator system as used on old cars and presumably for a dynastart.
The generator uses the armature to provide charging power. Now if this is connected to a battery it will draw current and actually function as a motor.
So first requirement is that the generator be disconnected from the battery with ignition on. This is done by a relay also called a cut out. This comprises a coil of fine wire connected output to earth that pulls the relay in when there is voltage being produced by the armature. The generator was able to produce power from, resiidual magnetism in the iron body and pole pieces of the field coils. Fixed outside the rotating armature. There is another coil on the cut out relay made of heavy wire o0f a few turns. This is connected in series with the output of the generator and the points (contacts of the relay) such that when the generator starts geneating the current flow through this coil reinforces the pull of the voltage sensing coil. Now when the engine stops the current trying to flow battery to generator will flow in the reverse direction so opposing the magnetism of the voltage coil and causing it to release the relay. So this is not just a relay but a specially designed (calibrated) relay. The spring tension of the relay is adjustable to enable the pull in voltage to be set.
Now the next part of the system is the regulator. The field current for the generator is fed from the output of the generator via the regulator contacts to the field coils and ground.
The regulator relay is again a coil of many turns connected output to ground. When the voltage rises to a set point the relay pulls in. In this case to open contacts. Again the spring tension is adjusted to set the pull in voltage. The contacts opening cut field coil current so reducing output. They typically fit a resistor across the contacts so that there is field current flowing at all times but this is increased by shorting the resitor when voltage is low. This relay typically chatters from open to closed at a ratio of open to closed depending on tthe output voltage. The output voltage of course depends on the charge state of the battery. So really only starts to open (reduce charge) when battery volts rise. The chattering of the relay and current switching meant that the points were a source of failure and needed maintenance.
In some systems there was also a current regulator. This consisted of a heavy coil on a relay in series with the generator output. Operating this relay would open contacts to again reduce or cut field coil current. Again the operating current was set by spring tension. The curent limiting designed to protect the generator from overheat (especially the brushes) from too much current.
Now a modern solid state replacement might consist of a diode in series with the generator output to stop battery current into the generator. Though volt drop might be detrimental to output power. So original cut out may be retained as fairly efficient.
The regulator part is better done with a transistor whose conduction can be easily varied depending on the oputput voltage. A zener diode is used as a reference and a power transistor used to actually control the fied current of 1 amp or so.
Current regulation if needed might easiest be done with the original relay system.
In some sophisticated systems like aircraft the regulator consisted of a voltage sensing coil whose armature operated to decompress a stack of carbon discs. The discs were compressed by a spring to present lower resistance to the field current. When the voltage sensing coil operated (at regulation voltage) the pressure was reduced on the stack of discs so increasing resistance. This system then had better reliability or longer life. ( called a carbon pile regulator)
Now this may help you understand how it is meant to work but sorry not much help at relay connections. good luck olewill
The generator uses the armature to provide charging power. Now if this is connected to a battery it will draw current and actually function as a motor.
So first requirement is that the generator be disconnected from the battery with ignition on. This is done by a relay also called a cut out. This comprises a coil of fine wire connected output to earth that pulls the relay in when there is voltage being produced by the armature. The generator was able to produce power from, resiidual magnetism in the iron body and pole pieces of the field coils. Fixed outside the rotating armature. There is another coil on the cut out relay made of heavy wire o0f a few turns. This is connected in series with the output of the generator and the points (contacts of the relay) such that when the generator starts geneating the current flow through this coil reinforces the pull of the voltage sensing coil. Now when the engine stops the current trying to flow battery to generator will flow in the reverse direction so opposing the magnetism of the voltage coil and causing it to release the relay. So this is not just a relay but a specially designed (calibrated) relay. The spring tension of the relay is adjustable to enable the pull in voltage to be set.
Now the next part of the system is the regulator. The field current for the generator is fed from the output of the generator via the regulator contacts to the field coils and ground.
The regulator relay is again a coil of many turns connected output to ground. When the voltage rises to a set point the relay pulls in. In this case to open contacts. Again the spring tension is adjusted to set the pull in voltage. The contacts opening cut field coil current so reducing output. They typically fit a resistor across the contacts so that there is field current flowing at all times but this is increased by shorting the resitor when voltage is low. This relay typically chatters from open to closed at a ratio of open to closed depending on tthe output voltage. The output voltage of course depends on the charge state of the battery. So really only starts to open (reduce charge) when battery volts rise. The chattering of the relay and current switching meant that the points were a source of failure and needed maintenance.
In some systems there was also a current regulator. This consisted of a heavy coil on a relay in series with the generator output. Operating this relay would open contacts to again reduce or cut field coil current. Again the operating current was set by spring tension. The curent limiting designed to protect the generator from overheat (especially the brushes) from too much current.
Now a modern solid state replacement might consist of a diode in series with the generator output to stop battery current into the generator. Though volt drop might be detrimental to output power. So original cut out may be retained as fairly efficient.
The regulator part is better done with a transistor whose conduction can be easily varied depending on the oputput voltage. A zener diode is used as a reference and a power transistor used to actually control the fied current of 1 amp or so.
Current regulation if needed might easiest be done with the original relay system.
In some sophisticated systems like aircraft the regulator consisted of a voltage sensing coil whose armature operated to decompress a stack of carbon discs. The discs were compressed by a spring to present lower resistance to the field current. When the voltage sensing coil operated (at regulation voltage) the pressure was reduced on the stack of discs so increasing resistance. This system then had better reliability or longer life. ( called a carbon pile regulator)
Now this may help you understand how it is meant to work but sorry not much help at relay connections. good luck olewill
<152587>
...
Do not really understand what you are trying to achieve here but the regulator should be marked. D-, D+, DF all connect to the relevant terminals on the Dynastart. B+ connects to the +battery terminal. Of the remaining 61 is fed from the ignition switch through the warning light the other terminal possibly fitted or a wire connected to the casing will be a ground (batt-). Incidentally, the wiring on the VSR does not appear to be of the correct cross section to connect 2 batteries, fire waiting to happen!
ghostlymoron
Well-Known Member
Thanks both for your comments. I'm not looking to change anything but just to understand how the present system works. Re the cable size to VSR, the max output from the generator is 170 w (14a) so I would have thought the 20a rated cable would be OK.
Incidentally, I've tidied up the wiring substantially since this photo was taken.
Sounds like the silver box has some likely points of failure. Chattering points and springs. May be good to carry a spare. Solid state sounds good.
Incidentally, I've tidied up the wiring substantially since this photo was taken.
Sounds like the silver box has some likely points of failure. Chattering points and springs. May be good to carry a spare. Solid state sounds good.
Last edited:
<152587>
...
Regardless of what the generator output is the VSR will connect the 2 batteries when it clicks in. This will allow the power from the primary battery to migrate to the secondary battery as a potential difference is present. The connection needs to be of a size to accomodate this, I would suggest 50mm.
ghostlymoron
Well-Known Member
I guess that this is what it looks like internally. Ignore the arrow!
Although probably not as pristine. I'm beginning to understand how it works.
Looks rather last century and I understand that there is a solid state equivalent which would be more reliable. Maybe I'll get one as a spare.
Re-VSR wire size. I think my main battery leads are 25mm2 so thats the max I can do. It's not the QE2
Although probably not as pristine. I'm beginning to understand how it works.
Looks rather last century and I understand that there is a solid state equivalent which would be more reliable. Maybe I'll get one as a spare.
Re-VSR wire size. I think my main battery leads are 25mm2 so thats the max I can do. It's not the QE2
Last edited:
William_H
Well-Known Member
I guess that this is what it looks like internally. Ignore the arrow!
Although probably not as pristine. I'm beginning to understand how it works.
Looks rather last century and I understand that there is a solid state equivalent which would be more reliable. Maybe I'll get one as a spare.
Re-VSR wire size. I think my main battery leads are 25mm2 so thats the max I can do. It's not the QE2
My guess is that this box pictured is the actual generator regulator as separate from the relays for starter energising. The coil closest to the camera will be the voltage regulator coil. That bracket at the arrow head can be bent to adjust the spring tension and so regulated voltage. Well really the voltage at which it starts to regulate after running full chat.
The far coil will be the cut out. A kind of voltage sensing relay but not to be confused with electronic control VSR for battery paralleling. Note the heavy wire outside coil that carries all the generator current to the battery. It is over a hidden fine wire voltage sensing coil. So charge current reinforces the relay operation (under voltage alone) but opposes the relay operation if current flows backwards. Again the spring tension can be adjusted to set the initial pull in voltage. You may be able to infer from the cil connections how it goes in the whole circuit. Sorry I seem to have forgotten how the generator light is wired or works. good luck olewill
VicS
Well-Known Member
There is a wiring digram in the MD1 Instruction book which Dylan has scanned and put on his KTL website.
Clearly though this is shows the control box with integral starter relay.
Clearly though this is shows the control box with integral starter relay.
oldharry
Well-Known Member
Solid state is a big improvement on the old mechanical regulators, giving a steadier and higher charge current. Usuallyunder £100, but you have to get the right one for your dynastart. The method of voltage regulation varies but some use an increasing voltage to raise the voltage output while others have to reduce the control voltage to increase output. Visualise it as variable resistance (which it isn't) either on the + feed reducing voltage or the - side increasing voltage to understand the difference. WHen I get home later this week I can check which way your unit works.
ghostlymoron
Well-Known Member
Olewill, if you look at the picture of my installation, you'll see that I have a separate black box relay.
William_H
Well-Known Member
I can't imagine why asolid state regulator will give more charge current than existing reg . Charge current will depend on the regulated voltage to induce more current into the battery but more likely this current will be limited byt he generator itself and its speed.
Control of voltage out of the gen is most efficently done by controlling the field current. More current more field magnetism so more output volts/current. I can't imagine how reducing voltage anywhere will increase current.
Just waffling again the advantage of an alternator is in the construction of the rotating parts. These are the field coil which is wound on an axis aligned to the shaft ie N to one bearing and S to the other. This field is then bent by pole pieces to give often 6 poles 3XN 3X S
on the perimeter of the part such that these pole piece heads move in close proximity to the pick up coils fixed on the inside of the case. The point is that this kind of rotating memeber can cope with extremely high rotation speed without flying apart. By contrast the rotating armature of a generator has heavy wiring to carry all generated current in a complex pattern susceptible to centrifugal force (and flying apart at high speed.
So an alternator can be run at high speed ie top engine revs by gearing such that even at idle it has a decent rotational speed and can charge at idle. Higher speed means more current capability.
By contrast a generator must be limited by gearing ratio (pulleys) to the max engine speed not exceeding the capabilities of the armature. So lower rotational speed at normal engine revs so less current supply capability. In addition becuase the current being passed to the rotating member is only field current and on lsip rings not commutator the brush mechanism is much more reliable than the generator where all current produced must pass the brushes and be switched by the commutator an inherently wearing process.
Starter/ generators are still used on small gas tubine engines on aircraft. The engines run at a much more constant speed so generator is set for a constant rotational speed. The starter function requires a much greater final speed for start so gearing ratios are more suitable to generator.
good luck olewill
ghostlymoron
Well-Known Member
I'm aware of the advantages of an alternator but I'm stuck with the Dynastart and MD1 engine.
VicS
Well-Known Member
If you wanted to, is it possible to add an alternator for battery charging etc., retaining the Dynastart for starting and perhaps charging the starter battery.? It is I believe a popular modification for those later engines that still had a Dynastart as original equipment.
