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Article #160Re: Alarm for auto temp and press?
From: Ed Price
Date: Sat, 27 Jul 2002 06:54
Date: Sat, 27 Jul 2002 06:54
30 lines
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2998 bytes
"Bob Wilson" <rfwilson@intergate.nospam.bc.ca> wrote in message news:uk4469678dlced@corp.supernews.com... > In article <0001HW.B9662A7A0081FD3711C75850@news.supernews.com>, > anon@example.net says... > > > >Would like to have in my car a high coolant temperature alert and low oil > >pressure alert combined and automated. Coolant monitor input should have > >calibration ability for custom adjustment for each vehicle. Pressure can be > >simple zero volt input trigger (I think most oil pressure crises are the > >result of loss of pressure, not simply the lowering of this). Output could > be > >either an audible alert or relay contacts to break ignition supply (or > reduce > >the supply voltage so as to get your attention) or sound an alarm. > > > >Does such a thing exist? Suggest you look into building a comparator circuit. Assuming that your gauges are electrical, then the sensor (thermistor for temperature and variable resistor for oil pressure) supplies a voltage which varies between two extremes. Tap the sensing side of the gauge and check the voltage range. You can get four comparators on a single chip. You may have to scale the voltage range, but you should be able to set a trip point on the comparator which corresponds to the physical value that you consider dangerous. Several comparators can be wired to light a single warning light and/or buzzer. Ed
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X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 112d1e,763bf32a0633cc62 X-Google-Attributes: gid112d1e,public X-Google-Thread: 111d0a,763bf32a0633cc62 X-Google-Attributes: gid111d0a,public X-Google-Thread: 107cee,763bf32a0633cc62 X-Google-Attributes: gid107cee,public X-Google-Thread: 10d137,763bf32a0633cc62 X-Google-Attributes: gid10d137,public X-Google-Thread: 103407,763bf32a0633cc62 X-Google-Attributes: gid103407,public X-Google-ArrivalTime: 2002-07-27 00:50:30 PST Path: arc1-ca.pugleaf.net!archiver1.google.com!news1.google.com!newsfeed.stanford.edu!canoe.uoregon.edu!logbridge.uoregon.edu!kibo.news.demon.net!demon!newsfeed00.sul.t-online.de!newsfeed01.sul.t-online.de!t-online.de!newspeer1-gui.server.ntli.net!ntli.net!cox.net!p01!news2.west.cox.net.POSTED!53ab2750!not-for-mail From: "Ed Price" <edprice@cox.net> Newsgroups: sci.electronics.basics,sci.electronics.design,sci.electronics.misc,alt.engineering.electrical,aus.electronics References: <0001HW.B9662A7A0081FD3711C75850@news.supernews.com> <uk4469678dlced@corp.supernews.com> Subject: Re: Alarm for auto temp and press? Lines: 33 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Message-ID: <Ysr09.28515$Fq6.2925506@news2.west.cox.net> Date: Sat, 27 Jul 2002 06:54:48 GMT NNTP-Posting-Host: 68.7.46.3 X-Complaints-To: abuse@cox.net X-Trace: news2.west.cox.net 1027752888 68.7.46.3 (Sat, 27 Jul 2002 02:54:48 EDT) NNTP-Posting-Date: Sat, 27 Jul 2002 02:54:48 EDT Organization: Cox Communications