[modeleng] Re: voltage controll

Alan,
Thanks for your response.
Unlikely as it seems, the design IS faulty. It is faulty in the sense of 
dimensioning the components. To give but one example; one of the 
transistors, that I managed to idenditfy, has B-E voltage over it of 20 
Volts, its maximum according to specs is 28 Volts. This should be at 
least 50-60 Volts, if only on account that its on a circuit board, that 
cuts a very strong magnetic field. I know of another genset, where te 
owner did manage to identify the thyristor,that it was only to be used 
up to 450 Volts, on a 380 Volts genset!!!(should be 600V min.)
etc.etc.
You are correct in stating that the principle is NOT faulty. These 
things would work perfectly if used under conditions, where they never 
had to power inductive (motors/transormers...)
users. They are sold as being capable of doing the former and the latter...
They also have a lot of "stress" as far as phase-balancing is concerned. 
While the specs give a wide 20% as being ok, the nature of the AVR and 
its build tell me other things

As for as your suggestion goes,about building one myself; I intend to do 
just what you mention. A big and widely spaced circuitboard, with plenty 
of room for the components to get rid of their heat. Propper heat 
sinking, if need be with a forced cooler, where needed.
The whole thing mounted away from the genhead, and easy to get to. and 
above all, build in a way, that allows for faulty components to be 
replaced; rather than the whole unit.
The circuit is to be made with propper components, from know brands, 
with specs than can be trusted. Also a bit of "over" dimensioning never 
killed any circuit; the opposite does; often..

The "next size" up, is an alternative I have looked into, but that would 
be an investment of at least 250 Euro. I still would have the problem of 
the infernal 'gunk'. I still wouln't have the diagram I want so much. On 
top of it all, I wouldn't be garanteed it would work at all! (since 
nobody has a circuit diagram, including the vendors that would be 
prepared to sell to private owners)
As far as costs go, I have build more circuits then I care to remember, 
and I know, that I , given a diagram and some more pointers and thoughts 
of you all, can build a solid working circuit for 50-100 euro's.
the price might be the same as the commercial ones, but I will not die 
on me at "the drop of a hat'
Many thanks
Regards
Patrick


Alan Stepney wrote:

>Going back to basics, to me it seems unlikely that the original design is 
>faulty or there would surely be many complaints and the set makers would 
>have changed it to a different make or type of regulator.
>
>The two major "killers" are  spikes or excessive heat, and I would guess 
>that the latter might be the problem.
>Would it be possible to start with a new board, but before using it, fix a 
>lot of heat sinking to it plus add a cooling fan to dissipate the heat.
>
>Alternatively, would the same board from the next size larger generator be a 
>better option?.
>
>Either of these might be easier than trying to build a new board yourself.
>
>
>Alan Stepney
>
>http://www.alanstepney.info
>Model Engineering & steam engine information pages 
>
>MODEL ENGINEERING DISCUSSION LIST.
>
>To UNSUBSCRIBE from this list, send a blank email to, 
>modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.
>
>  
>
MODEL ENGINEERING DISCUSSION LIST.

To UNSUBSCRIBE from this list, send a blank email to, 
modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.

Other related posts: