[Diy_efi] schematic critique (???)

[Mark Bowers & Family]

HI J,

I just looked at your schematic #3; getting closer....but still needs some
tweaks. I don't have any schematic SW anymore, but could sketch it up and
FAX to you sometime. Then you could post it for the rest of the guys to blow
away. Gotta FAX number??

And a 2N3904 is an alternate relay drive transistor, but does not support as
much current draw as the 2N2222. The 2N3906 is the PNP version which if used
may not require a logic inversion as I think someone mentioned.....

- Do you know the coil resistance of the output relay coil? This may be
important to make sure we size the output transistor correctly.
- Also, can you give some more details on the drive source to the circuit?
Is it some sort of sensor? (I am sure it is some sort of 1000+ HP
performance mod for a MotoGuzzi, but you can trust us...)
- Does this need to be a particularly fast response time? Adding capacitors
in the signal circuits will add time response delay (as well as filtering
out unwanted noise), so some care is needed to account for the desried time
response of the circuit.
- One final question: Is voltage #1 intended to be the reference that you
set, and voltage #2 the input form the sensor or whatever?

Are we helping yet????

Mark B.

PS My response cycle time is at least a day.....gotta work for a living.....


----- Original Message -----
From: Toyota Supra <turbosupramk3 at hotmail.com>
To: <diy_efi at diy-efi.org>
Sent: Monday, February 17, 2003 9:51 PM
Subject: Re: [Diy_efi] schematic critique (???)


>
> hey bill, i have modified the circuit per your and some others advice, i
> must say that i am thoroughly confused now with the different versions
that
> it has went through, so i am relying that this will function, else i won't
> know which values to alter ??? :)
>
> here is the latest photoshopped schematic, version 3.0
>
> http://68.7.7.84:8080/schematics/schematic3.psd
> http://68.7.7.84:8080/schematics/schematic3.jpg
>
> are the values and placements of the components on par as well? lmk,
thanks
> for the help all
>
> -j
>
>
>
>
>
>
> >From: Bill Washington <bill.washington at nec.com.au>
> >Reply-To: List for general do-it-yourself EFI talk <diy_efi at diy-efi.org>
> >To: diy_efi at diy-efi.org
> >Subject: [Diy_efi] schematic critique
> >Date: Tue, 18 Feb 2003 09:39:32 +1100
> >
> >J,
> >    The following are basic circuit comments, I have not looked at it
from
> >a functional point of view.
> >
> >1. Schematic 1 requires another protection diode on the relay drive
(Anode
> >to GND, Cathode to signal) to prevent the negative spike (when the relay
is
> >released from blowing the opamp.
> >
> >2. Schematic 2 :
> >a. Comment 1 applies.
> >b. series resistor reqd between opamp and transistor base
> >c. Transistor collector should go to +ve supply, Emitter should go to the
> >relay coil.
> >
> >Regards
> >Bill
> >
> >>
> >>Date: Sun, 16 Feb 2003 18:50:49 -0500
> >>From: "Toyota Supra" <turbosupramk3 at hotmail.com>
> >>To: diy_efi at diy-efi.org
> >>Subject: [Diy_efi] need schematic critique
> >>Message-ID: <BAY2-F94ArbDVL7IZQI0002de3e at hotmail.com>
> >>Content-Type: text/plain; format=flowed
> >>MIME-Version: 1.0
> >>Precedence: list
> >>Reply-To: List for general do-it-yourself EFI talk <diy_efi at diy-efi.org>
> >>Message: 1
> >>
> >>hi all,
> >>
> >>i need a schematic critique on the schematic housed below, it is in .jpg
> >>format or .psd
> >>
> >>http://68.7.7.84:8080/schematics/
> >>
> >>i have included the psd in case someone wanted to edit it to something
> >>better
> >>
> >>specifics on it are as follows :
> >>
> >>variable resistor input, ranging from 0 to 3.5vDC
> >>circuit is to kill signal to normally open relay at 3.2vDC
> >>i would like approximately a tenth of a volt of hysteresis
> >>
> >>
> >>below is a link that i would like to use to control the reference
voltage
> >>for pin 4 of the LM339 chip, will it work?
> >>
> >>http://www.mitedu.freeserve.co.uk/Circuits/Power/lm317.htm
> >>
> >>
> >>thanks to all that look at this
> >>
> >>-j
> >>
> >>
> >>
> >>
> >
> >
> >
> >_______________________________________________
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> >Diy_efi at diy-efi.org
> >http://www.diy-efi.org/mailman/listinfo/diy_efi
>
>
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