AUTOMOTIVE AUTOMATIC ENGINE START HELP????????

[JATEU_01]

Hi all,

I am trying to make a automatic engine start system for my motorcycle. i have the following power 12v switchable on-off relay, problem is i have the circuit but i need to incorporate a auto off, so that when the alternator is at a sertain voltage is will set the relay back to off. so i need a circuit that will turn off the relay at a preset voltage, can anyone help.

thanks for your time

 

[tansis]

Can you explain in more detail to clarify just what you want..

You want your motorcycle's engine to start automatically
to recharge the battery or is it a remote control start /
ignition system you require ?

 

[JATEU_01]

HI

the system i am trying to make is a one switch starting but i want to cut the sarter motor out when the engine is started properly. now the only way i can see of doing that is by detecting the voltage coming from the alternator, and then use that to auto shut off the starter

component i have is a 12v relay that switches on with one acutuation and then off with a following actuation

 

[pike]

he needs a momentary switch which turns on the relay, which starts the motor which provides ignition.

but instead of using human fingers to press the switch he wants some thing to detect the engine ignition and there fore cut the power to the starter motor.

oxygen sensor in exhaust
rpm detector
voltage detector at the starter engine( which also serves to generate electricity to recharge the battery)

one of the above would work.

 

[kurnia.2]

Isn't it basically a remote starter?

It can also use vacuum switch to detect if the engine has run.

 

[tansis]

Both Pike & kurnia.2 have made some good suggestions, I like particulary kurnia.2's.

Now Pike I suspect has fond memories of the yamaha "dynastart" system
where the alternator and starter motor are one combined unit connected directly to the crankshaft... sadly its low torque made it it unsuitable for all but two stroke machines. Modern machines, and by modern I mean mainly four strokes have a separate starter motor and alternator.
(the Honda "Express" actualy uses a clockwork starter mechinism and a flywheel magneto that my grandfather would of understood)

Now under english law it is not illegal to talk about build/ fit or even use remote engine starters, it only becomes a problem if you are CAUGHT using it!

"JATEU_01" may be hearing impaired or his machine devoid of a tachometer, possibly even devoid of feeling below the waist, though I grant you with these new water cooled bikes IT REALLY IS hard to know if the engine is actually running..

Nevertheless the question still reamians "JATEU_01",
tou have to be on the or in the bike to start it , therefore what is the problem holding down the the starter button till the engine catches ?
(bearing in mind a starter motor is to designed to dis-engage mechanically when the engine achieves self sustaining ignition)

 

[pike]

Now Pike I suspect has fond memories of the yamaha "dynastart" system

nope, I dont even have a license to drive. It just sounds logical to use the starter motor as an electrical generator.

 

[Nigel Goodwin]

nope, I dont even have a license to drive. It just sounds logical to use the starter motor as an electrical generator.

Unfortunately not, they perform completely different jobs - a starter motor wouldn't work at all well as a generator.

The Yamaha system refered to (a friend of mine had an RD200 many years ago!) effectively used two systems in a single casing - there were seperate brushes for the generator and the starter motor. One advantage of it was that the starter motor was permanently engaged, so you didn't get the usual starter motor noises - if you stalled it, you could restart it instantly, without anyone noticing :lol:

 

[JATEU_01]

FIRST OFF THANK YOU ALL FOR YOU HELP

ok so what circuit should i us to switch the engine off, i would like to use the easyiest detector ie once the engine is running smooth the alternator will produce a certain voltage, now what would i use to detect that....



thanks again


ps. there are no laws stating that you cant use remote starting

 

[Pommie]

a.

 

[jkmadsci]

You can use an opamp.

 

[JATEU_01]

How to use an OPAMP

how would i use and op in my circuit and how would it be used?