You're also going to have to use a 7805 voltage regulator to power this meter--it won't run off 12V without a negative supply, but it will run off 5V without one.
The 7805 regulator is a three-terminal device available at RadioShack for about 99 cents that takes 12V in and outputs 5V. The third terminal is connected to ground. You won't need to heatsink it for powering this meter. I would solder three wires to the 7805 and then stick it in some heatshrink tubing and shrink it down. Use the TO220 package 7805--this is the only one RadioShack sells.
The resistors needed for a 19.99V full scale reading are 1megohm and 10kilohm. I would recommend the use of 1% tolerance resistors for the greatest accuracy, but you will need to calibrate the meter. I would suggest calibrating it against a digital multimeter.
You will also want to connect the XDP terminal to the DP2 terminal so that the decimal point is in the correct place.
ok, this is SORT of making sense. so i DO need a regulator? also, on that pdf sheet under "applications" there are a bunch of circuit diagrams listed. which one should i follow when i install it?
and damn, i dont have a multimeter...
I got one from the Jegs catalog that plugs into the cigarette lighter, since I don't smoke it works out for me. Plus I can take it out when I want to and didn't have to modify the car.
Frank McCoy aka Mod-deth aka Mid Life Crisis aka SVT Doood aka mcgainer is a SCAM ARTIST
Pre98 Zetec - Some Mods
Originally posted by Rizzo: I got one from the Jegs catalog that plugs into the cigarette lighter, since I don't smoke it works out for me.
Plus I can take it out when I want to and didn't have to modify the car.
can you show me a link? i just think it would be a fun project to do something with that blank panel and a LCD display there would be pretty cool
and a LCD display there would be pretty cool