More DIY EGOR

[FR Wilk]

RE: More DIY EGORJJ,

But it is not a constant power system. That is not what I was describing. It
is a variable power (variable voltage) system to maintain a constant
resistance value of the heater element. The heater and the Lambda sensor are
separated slightly from each other and are not necessarily at the exact same
temperature. Exhaust gas will affect the sensor temperature more than the
heater temperature. But, the temperature at the heater is a good
approximation of the temperature of the Lambda sensor. Maintaining the
heater resistance (at a constant value) is a good attempt at stabilizing the
sensor temp.

Changes in hot exhaust gas will change the Lambda sensor's temperature and
that temperature change will eventually show up at the heater element as
change in resistance value. If more heat is being supplied by the exhaust
gas, then the power of the heating element should be reduced. And
vice-versa. Maintaining a constant heater resistance value in order to
stabilize its temperature. This is what I have been lead to believe.

FR Wilk
___________________________

> From: Jeroen Proveniers
>
> Sorry for jumping in, normally I only lurk
> No, at constant resistance it would dissipate a constant number of watts.
> When ambient temp rises the temp of the heater would rise too. The
> temperature would remain constant if the heater has a PTC effect. When
> temperature rises, resistance rises too, decreasing dissipated power. This
> way self-destruction of the heater is prevented.
> JJ
> >
> > From: 944 at technologist.com [mailto:944 at technologist.com]
> >
> > Am I understanding this correctly? The goal of the heater is
> > to maintain the
> > heater element at a constant resistance (say 3.5 ohms) . If
> > the resistance
> > of the heater remains constant, than the heating element is
> > assumed to be
> > keeping the sensor at a constant temperature. Is that correct?
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