Start stop switches in cars.

[ajlelectronics]

How are these typically configured please? I am toying with the idea of incorporating one into my new boat panels. I need a start and solenoid stop facility.

I see that they all have more than two pins, so is there some sort of "changeover" going on inside the button? I could arrange that electronically, but a button with a toggle would make life easy of course.

 

[sako243]

They are I think typically just momentary push buttons with the logic behind handled by an ECU.

After all most microcontrollers can be shut down completely consuming no power and the button attached to an interrupt to wake up the microcontroller which boots quickly and starts measuring how long the button was pressed for etc.

A remote control system I built the micro was completely off with a button attached as a rising edge interrupt. This would boot the micro and it would sample the button, do anything required and then shut down again.

 

[ajlelectronics]

They are I think typically just momentary push buttons with the logic behind handled by an ECU.

After all most microcontrollers can be shut down completely consuming no power and the button attached to an interrupt to wake up the microcontroller which boots quickly and starts measuring how long the button was pressed for etc.

A remote control system I built the micro was completely off with a button attached as a rising edge interrupt. This would boot the micro and it would sample the button, do anything required and then shut down again.

That is what I was expecting thanks, but my interest was piqued at the number of connecting pins.

 

[voipio]

A couple of the pins will be for the backlighting.

 

[Pigeon_Droppings2]

I was working on an old garage shutter door controller which had a similar sort of logic...each button push scrolled the controller thro a sequence of up-stop-down etc.

I was pondering if it might have an alternative use but ended up throwing it away.

 

[Ubique]

The switches generally have two sets of contacts, a NO & a NC so that the action is confirmed as a positive input - the same goes for brake pedal switches.

Edit: I think this will do what you want https://www.vehiclewiringproducts.c...sh-off-switch-with-led?variant=52615259980112

 

[Nomad]

Will parasitic battery drain be an issue if the boat is parked up for months?

Old style ignition key lock will cut all power (apart from any alarm etc), I guess a smart On / Off needs to either be awake at all times or do "something clever" to avoid a flat battery.
My 90s Renault car had been parked for 3 months and the "good when parked" battery was measuring millivolts due to drain from the remote locking, alarm, etc...

My 70s cars have no battery drain apart from the radio stations when parked up...

 

[ajlelectronics]

Will parasitic battery drain be an issue if the boat is parked up for months?

I intend to team it up with an ignition (keyed) switch. Replacements with the anti clockwise engine stop function don't seem common and Volvo want £300 for one of theirs. Hence thinking sideways.

 

[ajlelectronics]

Edit: I think this will do what you want https://www.vehiclewiringproducts.c...sh-off-switch-with-led?variant=52615259980112

I think it will need to be momentary for engine start and momentary for stop solenoid. I will have to arrange for some sort of toggle, with input from the rev counter to see if it is already running or not.

 

[Ubique]

Well if you're having a rotary keyswitch anyway.....

Ignition Switches

Vehicle Wiring Products

www.vehiclewiringproducts.co.uk

The four position diesel start switches are/were popular on plant equipment

 

[dieselman]

You could fit an Energise to stop controller and a standard automotive type key switch. See example https://capricorn-controls.com/wp-content/uploads/2023/01/ETS200-Spec.pdf

I know the type of switch you mean, a friend installed one on his boat from L-R, it has Stop, Off, Run, Start. Strangely the Stop selection isn't return to Off.

From the previous post ignition switch 4 Position, T773 would perform that function.

 

[ajlelectronics]

Well if you're having a rotary keyswitch anyway.....

Ignition Switches

Vehicle Wiring Products

www.vehiclewiringproducts.co.uk

The four position diesel start switches are/were popular on plant equipment

The issue is that the Volvo switch has a "turn anticlockwise against the spring" to activate the stop solenoid. Every switch I have found so far is missing that function.

 

[ajlelectronics]

You could fit an Energise to stop controller and a standard automotive type key switch. See example https://capricorn-controls.com/wp-content/uploads/2023/01/ETS200-Spec.pdf

I know the type of switch you mean, a friend installed one on his boat from L-R, it has Stop, Off, Run, Start. Strangely the Stop selection isn't return to Off.

Yes, that is the type of thing I had in mind and keep a standard ignition switch. I think that I could come up with a better implementation though.

 

[Ubique]

That's an odd one, never come across that - usually it's 'remove supply from fuel solenoid' which works as a failsafe, 'energise stop solenoid' would theoretically allow a sequential diesel engine to run-on until the fuel tank is empty.

 

[dieselman]

That's an odd one, never come across that - usually it's 'remove supply from fuel solenoid' which works as a failsafe, 'energise stop solenoid' would theoretically allow a sequential diesel engine to run-on until the fuel tank is empty.

Boat engine bays get hot due to lack of fresh air movement, so solenoids are off other than when required. Most boat engines are mechanical stop, so a system had to be incorporated for that.
There is an additional benefit for reliability...an electrical failure won't stop the engine. It's better to have to manually stop the engine when back in port than have it fail in rough weather at sea.

 

[dieselman]

The issue is that the Volvo switch has a "turn anticlockwise against the spring" to activate the stop solenoid. Every switch I have found so far is missing that function.

You could fit the standard unsprung switch and a buzzer/klaxon/fog horn when in Stop mode.

 

[m_c]

I've worked on a couple little Kubotas which energise the stop solenoid for a few seconds when you switch the ignition off, which is handled via a time delay relay.

Depending on what approach you'd like to take, there are industrial time delay relays that can be wired to activate briefly when power is removed from the trigger feed.

 

[Misterg]

Fit a 3 or 4 position switch (depending on whether you have glow plugs / preheat) and a push button for stop.

e.g.

Waterproof Boat Key Starter Switch with 4 Positions

AG 4 position engine key start switch (709553) comes with two keys. Key start ignition switch for Petrol or diesel engines without heat start.

www.asap-supplies.com

You really, really want the engine to start when needed, so keep things as simple and robust as possible, and preferably waterproof. (You can get out and walk on the canal if you have to; not so easy in the Bristol Channel!)