laser motion detector starter

Hey, that's a cool page. I put it in my favorite places, so I can look at it again later. I'm good with relays and switches and wires.....but I really need to expand my knowledge of the other stuff. So it's a Mitsubishi Lancer, it's not very old, and I assume it's in good running order? When installing remote starters in late-model Mitsubishis, I program my remote starter's cranking time for 0.8 seconds, which seems to work perfectly. My co-workers leave the unit set at its default 1.0 seconds, resulting in a slight, but not objectionable, overcrank. In both cases, customers have not come back with complaints, even in winter, so I assume that's a good cranking time for you to use too. So anyway, I assume you know how to work that 555 timer........ are you able to set it for approximately .8 or 1 second of output? You could use that output to drive a relay, to trigger the car's starter wire........   does the 555 put out a negative or positive trigger? I can tell you how to wire up the relay if you want. I assume your plan is to cut the car's factory starter wire in half, thus disabling the key from starting the car........... and then use your setup to drive the "engine side" of the wire you cut. Right? Regardless of how you do this, I would strongly recommend a hidden toggle switch, to bridge the Mitsubishi's starter wire back together as factory whenever necessary. There are several reasons for this: -If you return to the dealer for service, they won't be suspicious you've modified anything. -Valet parking attendants, car wash people, family members, friends, etcetera, can drive the car without confusion. -If any of your system fails (and it's experimental, so you should be prepared for occasional failure), you'll have a backup. -If it's incredibly cold, or your car falls out of tune, you'll be able to crank the starter for as long as you need to, rather than being constrained by the output from the timer.

you are correct on all accounts. the timer puts out a positive voltage equivilent to the power source which in this case would be 12v+ the only limitation to time with this circuit is the resister and capacitor that you use on it. thats how the time is actually adjusted. the trigger can be source (just the touch of your finger on a bare wire will trigger it). its actually a really neat little circuit that can have many uses. and if you look at that webpage there are a few diffrent types of that circiut. the 555 timer can be found at any component shop and radio shack still sells them as well. anyways thanks for all your input and help im sure i will come up with something shortly and i will let you know when i do.

ok how about this. timer circuit powers a relay at say 10 volts, 12 volt rpm wire also feeds into the other side of relay. so circuit powers up and kicks relay on, when moter starts the 12 volt rpm wire goes hot and powers the relay into the other direction killing power to the starter. since the rpm wire will have the higher voltage it would over power the circuit power right? would that work or not?

Hmm, that's an interesting question; I don't know. I am not sure how the Mitsubishi's engine computer and instrument cluster work......you may (or may not) be able to access the tachometer signal behind the instrument cluster. I know it's available on a late-model Eclipse, so probably on your car too. For the typical remote starter install, we often use a spark coil or fuel injector as our tachometer signal.... Basically, the coil or injector will usually have two wires. One receives power with ignition. The other wire.......the car's engine computer applies a ground when it wants spark (or fuel)......the ground goes away when spark or fuel is not desired. Obviously, as the engine rotates, the spark plugs and fuel injectors are constantly, rapidly, being turned on and off. If you were to put a test light on one of these wires, with the engine running, you would see the light flashing rapidly.......and flashing faster as you rev the engine. I know that many remote starter installation manuals refer to these wires as AC, but I think a better description is that it's simply a DC ground, being switched on and off rapidly. (By the way, even if you do get the direct tach signal that goes to the instrument cluster, it behaves pretty much the same way.) I don't know how you could use that signal to command your relay to stop cranking the starter. What is your ultimate goal? Simple and fast and easy......or are you interested in taking the long route, and learning stuff for fun, and trying to make it slick and smooth as humanly possible? The reason I ask is because, if you just crank the starter for a fixed .8 seconds, I feel confident it's going to successfully start the car probably 49 times out of 50, and things will be fine. It'll just be that once in a while when you've left the car sitting for a week, or you've picked up some minor mechanical problem you haven't had time to fix yet, or you've traveled to somewhere that's super-cold and the car sat all night.........it'll only be times like those when you'd need to flip your hidden switch, and start the car the regular way with the key. If it didn't work reliably at that time setting, my co-workers and I would have seen a great deal of customers returning with complaints, and we haven't. The way I've installed the remote starters is in voltage-sensing mode.....there's no tachometer signal....it just cranks the car's starter for the predetermined .8 seconds. If that wouldn't start the car reliably, the customers would be back in a matter of days.

i basically just want to do this to be diffrent along with learning something new. everything will be in a test situation first off with it not even being in the car. on the bench with a powersupply. the car sits for a week at a time anyways since i have a work supplied truck. so it only gets used on the weekends. but even then it starts right away with no problems. so i will play with the circuit and get it to the .8 seconds (or as close as possible) and put it in test situation first. if it succeeds the way i want it to then i will install it in the car and cross fingers that it works. but it seems this project will be put on hold for right now till some things around here settle down. i will take into account all that you have told me and i will post back once i get this done. thanks for all your help its greatly appreciated.