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How to wire a relay to come on at 3000rpm
Posted: Fri Sep 25, 2009 10:24 pm
by DR Frankenstine
I want to wire an injector to spray at 3000rpm's . Im going to have two extra injectors. One will come on at 1.5lb boost the other at 3000 rpm. I need to know how to wire the second injector up please.....
Posted: Fri Sep 25, 2009 10:39 pm
by chimpboy
Get something like this:
http://cgi.ebay.com/ebaymotors/ADJUSTAB ... 06.c0.m245
... and hack it to operate a relay instead of (or as well as) the lamp.
Easiest bodgy method I can think of.
Posted: Fri Sep 25, 2009 10:48 pm
by -Scott-
Not really sure. Tacho with a shift light? Use the shift light output to trigger the relay?
It's probably possible to find some form of process controller with a frequency input; I would expect them to start around $200.
If you're into electronics, some form of high-pass filter feeding into a voltage sensing circuit. Sized appropriately, voltage would increase with frequency (i.e. from ignition circuit), then adjust the trigger for the relay to come on somewhere around 3000rpm.
Edit: the Chimp beat me. Looks like the cheapest & simplest option.
Posted: Fri Sep 25, 2009 10:56 pm
by chimpboy
If you did go the el cheapo shift light option, I think you'd want to make sure it runs an incandescent globe not an LED, if it runs an LED it might not be able to trip a relay... not sure.
Posted: Fri Sep 25, 2009 11:52 pm
by Simonc3
Posted: Sat Sep 26, 2009 1:50 pm
by -Scott-
chimpboy wrote:If you did go the el cheapo shift light option, I think you'd want to make sure it runs an incandescent globe not an LED, if it runs an LED it might not be able to trip a relay... not sure.
That's a real possibility - but there are some simple workarounds. I've had to install a simple transistor circuit so an electronic pressure switch can switch a solenoid. Four years later, still going strong.
The Jaycar kit looks the goods.
Posted: Sat Sep 26, 2009 2:20 pm
by chimpboy
-Scott- wrote:The Jaycar kit looks the goods.
x2, good find.
Posted: Sat Sep 26, 2009 10:32 pm
by Goatse.AJ
chimpboy wrote:-Scott- wrote:The Jaycar kit looks the goods.
x2, good find.
X3
led
Posted: Sun Sep 27, 2009 10:17 pm
by DR Frankenstine
Thats exactly what I need. Thanks a heap
Posted: Mon Sep 28, 2009 8:26 am
by Red Dog 4x4
Thats what i have running a shit light on my TD42 works perfect..
Posted: Mon Sep 28, 2009 9:06 am
by stuee
For those interested in all the electronics kits jaycar do for cars then check out:
http://www.jaycar.com.au/productView.as ... BCATID=662
I got given one for free when I bought a heap of stuff there. Quite a handy book. Goes over how each kit works and in what way it can be used. Worth the money IMO if you like tinkering with you car.
