Kill Switch - Normally Closed, or Normally Open? - 02 CBR600 F4i
Senior Member
Joined: Aug 2010
Posts: 805
Likes: 1
From: NJ
ok good i thought i was losing my mind for a second, i was hoping i learned something in my engineering years. but either way....would the answer be normally open since its normal rest state is the kill switch being off when the bikes not and the circuits not being activated? Or would its normal rest state be considered when the bike is running which would make the circuit normally open? How would you determine the normal state for a system like this?
Im assuming since when its active and functioning its a closed circuit so the rest state would be open? is that how it works? I effin hate electrical....
Im assuming since when its active and functioning its a closed circuit so the rest state would be open? is that how it works? I effin hate electrical....
Track junkie & modaholic
Joined: Aug 2011
Posts: 1,847
Likes: 2
From: USA
I emailed the guy who helped me figure out how to wire a rfid ignition on the subject to further help me understand after dirt blew my mind. this is what I got. It helped but I had to read a second time to catch everything.
Hi Christian
Was looking forward to hearing how you made out.
Yes - NO - 'Normally Open' means just that - no continuity through the switch in its standard resting condition
And NC - 'Normally Closed' means that pair of contacts WOULD have continuity when in standard condition
And then when you operate the switch (or relay) the opposite happens and the NO closes and the NC opens
i.e. with a 5 pin relay, the 30 - 87 contacts are the NO - they are open when the relay is not energized (however when relay IS energized, these contacts 'make')
and 30-87a are the NC contacts - these are normally connected when relay is not energized (however the open or disconnect when relay is energized)
With a relay with both 87 (NO) & 87a (NC) that is also sometimes called a 'changeover' relay
30 is the common and that input is switched to either 87 or 87a
for example on Triumphs, ignition fed power is on the 30 terminal and normally connects through the 87a to the headlights
But when you press the start button, it energizes the relay and connects the 30 to the 87 which goes to the starter solenoid
i.e. it simultaneously disconnects the headlights (to maximize battery current during starting) and enables power to the starter solenoid.
It is called changeover because it changes the input to one output or the other
Of course when the start button is released, it de-energizes relay so switches power off from the starter and restores to the headlights
So the zener worked as planned and bike started it appears?
That was only part that was 'third-hand' for me - have no personal experience of it but found that in a search
So it's good to have it validated.
You'll have to send some pics
Any time you have further questions, be glad to help if I can
Cheers
Was looking forward to hearing how you made out.
Yes - NO - 'Normally Open' means just that - no continuity through the switch in its standard resting condition
And NC - 'Normally Closed' means that pair of contacts WOULD have continuity when in standard condition
And then when you operate the switch (or relay) the opposite happens and the NO closes and the NC opens
i.e. with a 5 pin relay, the 30 - 87 contacts are the NO - they are open when the relay is not energized (however when relay IS energized, these contacts 'make')
and 30-87a are the NC contacts - these are normally connected when relay is not energized (however the open or disconnect when relay is energized)
With a relay with both 87 (NO) & 87a (NC) that is also sometimes called a 'changeover' relay
30 is the common and that input is switched to either 87 or 87a
for example on Triumphs, ignition fed power is on the 30 terminal and normally connects through the 87a to the headlights
But when you press the start button, it energizes the relay and connects the 30 to the 87 which goes to the starter solenoid
i.e. it simultaneously disconnects the headlights (to maximize battery current during starting) and enables power to the starter solenoid.
It is called changeover because it changes the input to one output or the other
Of course when the start button is released, it de-energizes relay so switches power off from the starter and restores to the headlights
So the zener worked as planned and bike started it appears?
That was only part that was 'third-hand' for me - have no personal experience of it but found that in a search
So it's good to have it validated.
You'll have to send some pics
Any time you have further questions, be glad to help if I can
Cheers
Nov 2011 ROTM
Joined: May 2010
Posts: 655
Likes: 0
From: O-Town
Its not that complicated guys.
First off buy a "Kill Switch", don't drill or screw into anything. Thats the crap we had to do WAY back in the day to go down the track but it's ugly and problematic over time.
Just search for lanyard or tethered kill switch. They are stock on watercraft and some ATVs.
Basically its going to be "open" when the lanyard is pulled and "Closed", meaning it WILL pass current when the lanyard clip is in place. All you need to do is put it inline with anything that will kill the engine. Easiest spot is the find the 12v ignition source off the bars and wire the switch inline with that so when you pull the clip off the lanyard it cuts the power to the ignition circuit.
Its just that simple.
Good luck.
First off buy a "Kill Switch", don't drill or screw into anything. Thats the crap we had to do WAY back in the day to go down the track but it's ugly and problematic over time.
Just search for lanyard or tethered kill switch. They are stock on watercraft and some ATVs.
Basically its going to be "open" when the lanyard is pulled and "Closed", meaning it WILL pass current when the lanyard clip is in place. All you need to do is put it inline with anything that will kill the engine. Easiest spot is the find the 12v ignition source off the bars and wire the switch inline with that so when you pull the clip off the lanyard it cuts the power to the ignition circuit.
Its just that simple.
Good luck.
Last edited by zaqwert6; May 5, 2012 at 08:13 AM.
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