Homemaid A/F guage how to??
03-27-2002, 01:13 PM
#1
Honda-Tech Member
Thread Starter
Homemaid A/F guage how to??
I was looking for that old topic on how to make your own A/F guage....couldn't find it...if anyone can link me, or explain what materials I need I'd appreciate it...I'm working on a project that I would like to use a similar approach on.
Thanks
Thanks
03-27-2002, 10:05 PM
#3
Honda-Tech Member
Join Date: Mar 2002
Location: Portland, OR
Posts: 2,178
Likes: 0
Received 0 Likes
on
0 Posts
Re: Homemaid A/F guage how to?? (On Point EK)
http://www.scirocco.org/
Go to the 'Tech Procedures' section and then 'Misc.' section There's some instructions on building one that should work for a honda...I actually built one over xmas and haven't got around to testing it (since I have a 'real' one installed) but, I think something might be wrong with the schematic on there...OH, also...you can get the chips for TOTALLY FREE. I did that. Got 5 of each for nothing, no shipping even and then just needed to buy the LED bar and misc crap from radioshack. good luck, lemme know if it works.
Go to the 'Tech Procedures' section and then 'Misc.' section There's some instructions on building one that should work for a honda...I actually built one over xmas and haven't got around to testing it (since I have a 'real' one installed) but, I think something might be wrong with the schematic on there...OH, also...you can get the chips for TOTALLY FREE. I did that. Got 5 of each for nothing, no shipping even and then just needed to buy the LED bar and misc crap from radioshack. good luck, lemme know if it works.
03-27-2002, 10:14 PM
#4
Honda-Tech Member
Re: Homemaid A/F guage how to?? (SuperDragII)
Wish I had a "home maid". Maybe one with some electrical experience so she could build me one of those homemade A/F gauges. 
03-27-2002, 10:17 PM
#5
Honda-Tech Member
Join Date: Nov 2001
Location: pa, usa
Posts: 971
Likes: 0
Received 0 Likes
on
0 Posts
Re: Homemaid A/F guage how to?? (93LSivic)
was it this one? http://www.techedge.com.au/vehicle/wbo2/wbo2.htm
03-28-2002, 07:58 AM
#6
Honda-Tech Member
Thread Starter
Re: Homemaid A/F guage how to?? (93LSivic)
Wish I had a "home maid". Maybe one with some electrical experience so she could build me one of those homemade A/F gauges.
thanks for the replies, got what I need!
03-28-2002, 07:09 PM
#7
Honda-Tech Member
Re: Homemaid A/F guage how to?? (SuperDragII)
LM3914
The A/F gauges are based off this chip. Its just a LED segment driver with a resistor ladder and some op-amps inside to do some comparisons....if you take a look at the datasheet, you'll see what I mean. National also offers an O2 buffer, or Lambda buffer if you will, although the input impedance of the 3914 is high...its just something to think about.
As you can see, you can daisy chain a couple of these together to extend the display resolution (instead of 10 LEDs displaying .1-.9V, you can have 30 LEDs displaying the same range).
Now, please note, you can build one of these things as a very simple voltmeter. You don't HAVE to just hook it up to the O2...you can hook it up to the MAP, IAT, ECT...anything that provides a voltage output.
All the LM3914 does is take a DC voltage and light up the appropriate LEDs.
Lets say you did want to measure MAP output...since the MAX output on one of these is in the neighborhood of 3V....just provide a 3V reference to the chip (which basically tells the chip that at 3V, all the LEDs will be ON), along with the MAP signal...and voila'...simple voltmeter.
The A/F gauges are based off this chip. Its just a LED segment driver with a resistor ladder and some op-amps inside to do some comparisons....if you take a look at the datasheet, you'll see what I mean. National also offers an O2 buffer, or Lambda buffer if you will, although the input impedance of the 3914 is high...its just something to think about.
As you can see, you can daisy chain a couple of these together to extend the display resolution (instead of 10 LEDs displaying .1-.9V, you can have 30 LEDs displaying the same range).
Now, please note, you can build one of these things as a very simple voltmeter. You don't HAVE to just hook it up to the O2...you can hook it up to the MAP, IAT, ECT...anything that provides a voltage output.
All the LM3914 does is take a DC voltage and light up the appropriate LEDs.
Lets say you did want to measure MAP output...since the MAX output on one of these is in the neighborhood of 3V....just provide a 3V reference to the chip (which basically tells the chip that at 3V, all the LEDs will be ON), along with the MAP signal...and voila'...simple voltmeter.
Thread
Thread Starter
Forum
Replies
Last Post