It is called a rectifier-regulator because the rectifier (the bridge)
also does the regulating; there is no separate regulating stage.
Two of the four diodes of the bridge are replaced by a diode-cum-switch
(a thyristor) to make that possible.
At the beginning of a phase the thyristor in the conducting branch does
not conduct.
The switch control function switches the thyristor on with a delay that
depends on input AC voltage (RPM) and output DC current (load).
It increases / decreases the delay when the (average) output DC voltage
is too high / too low.
The delay would probably be best controlled in terms of phase angle but
in practice is most likely done in terms of time.
https://en.wikipedia.org/wiki/Rectifier has a nice animation half way
the page.
The DC-output is extremely noisy - more than14V peak-to-peak for a 14V
DC average output. A large capacitor across the DC output terminals is
generally prescribed.
Regards,
Jan
On 1/21/2014 2:59 PM, Max Cointe (Free) wrote:
>
> Hi There,
>
> Excuse my french but as far as I remember from my initial training in
> electronics (in the 70's) a bridge of diodes will transform AC
> input(sinusoidal signal) in semi-sinusoid output which will be "transformed"
> in DC voltage by the action of a capacity. That DC output will be
> proportional in value to the input which is itself proportional to value of
> RPM of the alternator and to the consumption. At the output of the bridge is
> the input of the regulator which will act to maintain constant its own DC
> output, more precisely to regulator the output DC current so that the output
> DC voltage is at a standard level defined to have the battery correctly
> charged ie 14.5V for the SH and 13.8V for the Ducati.
> My two cents
>
> Max Cointe
> mcointe@free.fr
> F-PMLH Europa XS_TriGear
> Kit #560-2003 912ULS/AirmasterAP332 490 hours
>
> F-PLDJ DynAro MCR 4S
> Kit #27-2002 912ULSFR/MTProp MTV7A 1600 heures
>
>
> -----Message d'origine-----
> De : owner-europa-list-server@matronics.com
> [mailto:owner-europa-list-server@matronics.com] De la part de Jan de Jong
> Envoy : mardi 21 janvier 2014 13:59
> : europa-list@matronics.com
> Objet : Re: Europa-List: Re: Ducati rectifier/regulators
>
> Equally respectfully - "dumping to ground" is not dumping, but connection to
> the negative DC output terminal.
> I attach a little OpenOffice drawing that hopefully clarifies (I hope that
> works).
>
> Regards,
> Jan
>
> On 1/20/2014 11:21 PM, Greg Fuchs wrote:
>> --> <gregoryf.flyboy@comcast.net>
>>
>> Respectfully, I believe that the circuit configuration that you are
>> thinking of is incorrect, Jan de Jong.
>>
>> The SCR's do EXACTLY 'dump' the AC output DIRECTLY to ground.
>> When one end of the thyristor connects to the alternating current
>> output of the coil, and the other end to ground...then that is all
>> they can do but short the AC output to ground. It is not acting as a
>> PWM-like device at all, simply a grounding device. Call it a
> direct-connect.
>>
>> You mention heat. The direct-connect method is the best way to deal
>> with the heat. The forward voltage drop of the 'dumping' device is
>> low, and the current does not need to go through the diodes at all,
>> which are bypassed...hence your lowest heat output.
>>
>> Since the 'dumping device' connects the alternator output directly to
>> ground, without going through the diode, what is the power dissipated?
>> While in the dumping mode, lets say the current to dump was 10
>> amps(I'll use your generously supplied information, so I don't have to
>> look up specs) it would be 1.1V * 10 amps. That's it. 11 watts. That
>> is much better than the 18 Watts in your configuration.
>>
>>> (
>>> a failure mode for the Ducati device is reportedly the loss of
>>> continuity
>> of a diode pill attachment through thermal >cycling; fitting external
>> parallel diodes has been proposed as a solution; replacing the whole
>> device seems more
>>> sensible
>>> )
>> Well, maybe so! However, if the failure mode is a loss in continuity,
>> that would mean the diodes are opening. That would also mean that
>> connecting the external diodes to the regulator would bring it back to
> life!
>> Regards,
>> Greg
>>
>>
>>
>> -----Original Message-----
>> From: owner-europa-list-server@matronics.com
>> [mailto:owner-europa-list-server@matronics.com] On Behalf Of Jan de
>> Jong
>> Sent: Monday, January 20, 2014 7:40 AM
>> To: europa-list@matronics.com
>> Subject: Re: Europa-List: Re: Ducati rectifier/regulators
>>
>>
>> Re two-phase bridge rectifier/regulator.
>> The 2 thyristors in the rectifier bridge do not short the AC input or
> "dump"
>> anything.
>> On the contrary, they disconnect the DC output from the AC input when
>> the output voltage threatens to exceed the set voltage.
>> All output current passes through one branch of one diode and one
>> thyristor in series half the time and through the other identical
>> branch also half the time.
>> Heat development is proportional to the output current and the voltage
>> drop across a branch.
>> Voltage drops increase somewhat with current, so heat development
>> increases more than linearly with output current.
>> In the Ducati device the diode is reportedly a MR2510 pill (typically
>> 0.75V at 10A, 0.8V at 20A), the thyristor can be a 2N6504 (typically
>> 1.1V at 10A, 1.3V at 20A).
>> So at 10A the two branches of the bridge are each expected to generate
>> 0.5 x (7.5 + 11) = 9.25W (total 18.5W) of heat.
>> And at 20A the two branches of the bridge are each expected to
>> generate
>> 0.5 x (16 + 26) = 21W (total 42W) of heat.
>>
>> (
>> a failure mode for the Ducati device is reportedly the loss of
>> continuity of a diode pill attachment through thermal cycling; fitting
>> external parallel diodes has been proposed as a solution; replacing
>> the whole device seems more sensible
>> )
>>
>> Cheers,
>> Jan de Jong
>>
>
>
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