DIY-WB02 display
rr
rrauscher at nni.com
Thu Mar 7 21:02:53 GMT 2002
The UEGO controller portion of the circuit will run on
voltage as low as 11 volts. It also draws < 25 mA, just
don't quote me on that number. I don't have my notes in
front of me.
It is the heater circuit that requires the minimum of 13
volts @ ~ 1A.
BobR.
On Sun, 3 Mar 2002 21:13:23 -0500
"Clare Snyder" <clare at snyder.on.ca> wrote:
>
> Thanks to Bruce Roe for his input and listening ear, I
> think I have solved
> my display connundrum for my DIY-WB02 test unit.
> I have a lab grade milliameter mfg by Yokagawa in the mid
> seventies -
> somewhere around 5 inches square- with a nice mirrored
> scale, sensitive to
> 0.1ma full scale.
> By putting 14250 ohms and a red LED in series with this
> meter, it will read
> 1.3 to 2.8 volts - just about perfect for our purposes.
> By adding a 25000
> ohm resistor in series for free air calibration, it will
> read roughly 5.25
> volts full scale, and a switch will short that resistor
> out for normal
> operation.
> 14.4 will be roughly 3/4 scale.
> If I do not compress the scale, and let the meter read
> from 1.4 to 4 volts,
> 14.4 will be center scale and the operational range will
> be roughly 3/4
> scale. Either way it sounds good - what say you?
> The circuit board will fit right inside the case - the 5
> leads for the
> sensor will attatch to the existing 5 binding posts. A
> set of power leads
> will need to be added.
> Now - another question. Aside from the heater current,
> how much does this
> baby draw? Reason I ask is, could we (I) add a 1.5 volt
> battery inline with
> the power from the car to get the board voltage to stay
> consistantly above
> 13 when running off battery?
>
> ----- End of forwarded message from
----- End of forwarded message from owner-diy_efi at diy-efi.org -----
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