Lockup Circuit

[Paul1566]

Have been playing and would like some feed back on a simple Lockup Circuit with panic brake overide.
Circuit uses 3 cheap car type change over relays.
Simple idea that relays 1 & 2 latch to engage lockup and in the case of panic or wanting to remove lockup simply touch the brake pedal.
Most of the time when trundleing along you only need to back off to slow down and not brake every 20 yards.... some muppets do mind, followed a few in my time.
Suppose descent control with it on is not possible due to the brake off function but more use when pulling up hill and you want it to lock lower down the revs.

[Apache]

Ahhhh, relay logic! Been a long time...

Will have a proper look when I have less beer in my veins

[Paul1566]

Cheers andy knew you would be of help.
I'm old school so its relays and switches no multi legged black things for me.

Did spend 12 years as a electronic engineering technician and understood bugger all i was shown, spent more time on the mechanical side,
mostly nicking parts and building model boats and cars.
Then spent 3 years working on control panel drawings, all was basic relay logic and huge switches that need winding up to actuate them.
Caked me pants when me first job was to do circuits to control this massive lift bridge up north somewhere.
Had visions of getting wires crossed and cars plumitting off the other bank cus the barrier control was not wired right.



.

[Paul1566]

Bumptitybumpbump........

[BUSHWHACKER]

Bumptitybumpbump........

He's still pi**ed!


I like it anyway, especialy the black background.

[Paul1566]

I'm chief heep big CAD monkey so i spend all day using autocad with a black background.
Black don't hurt your eyes so much as white and colours stand out better.

Found a write up online, need to check my ecu is the same for the wire location.




Gunna mount the switch down here like this...


Had athought do i need diodes across the coils as rings a bell in my head for some reason, if so which way round ?

[Apache]

Diodes on the coils are a good idea. The anode goes to the positive side of the coil - in other words, the end with the stripe goes to the positive end. This is so any back-EMF is shorted out by the diode rather than by your ECU. 1N4001's will do fine, and are available from Maplin in Blackpole

Are those pics yours? Nice and neat, and same place I put my switch too

[Paul1566]

Got them from this write up http://www.toyotasurf.asn.au/forum/v...ic.php?t=12654
About halfway down the page.
They do mention another way to release the lockup would be to wire the live feed from solenoid 2,
this drops out automatically when droping to first gear giving a first gear failsafe.
But this would mean sol2 and sol3 are running of the same supply.
Only reason i am using relays is to get the latching effect which is capable of being disconnected via
another signal from the brake or as i said the sol2 feed going down.

[Paul1566]

Revised curcuit for your perusal....

[Apache]

TBH, having used it for a while, I haven't felt the need to add a failsafe. It's just like a manual. It starts to judder if revs to low for a gear, so just like a manual you instinctively 'know' when to deselect before that happens.

[gwh200]

Guess what... For the last month I have had a data logger attached to the gearbox ecu, the engine ecu and the tps. It collects any data signals generated, ie every time a change occurs. I looked at it recently and have come to the firm conclusion that any system designed to enable lock up, requires a "permit" system. This would take into account throttle posistion,velocity,etc, but would "flag" any potential issue that would precipitate lock up being deactivated. The permit system would look at the conditions every second or so and decide what was necessary. The model I came upwith seems to show that lock up could be made and not auto deactivated till you lost 15% of velocity/rpm over a given span of time. This is just simply measured as a function of effort against three conditions. I'm collecting the data,as this shows an infinite amount of conditions, but also some telling ones. The control could also over ride the overdrive if necessary. This would enable low speed/ higher rpm conditions to be met. It's all pure conjecture at present... And it would need an apache to build it.

[Paul1566]

Found a good read here http://www.autoshop101.com/forms/h16.pdf

Explains the relationships between each requirement to achieve lockup.
Apparently brake all ready disables lockup unless its hardwire overiden.
Also explains solenoid sequence so using Sol 2 to control supply to manual
lockup would in theory drop it out if the vehicle reduced speed enough to
engage 1st gear, so anti stall sorted.
Not sure about the fact that Sol 2 is off when in overdrive, but if you reach
overdrive your locked by the ECU anyway.
Just means if you drop speed too much you will need to re engage lockup.
The only reason i am looking at this is when trawling along under the 50mph
ECU lockup speed that it is very annoying when the engine
just keeps reving at the slightest throttle increase instead of applying power
to the wheels if you know what i mean.

Think this will be my final design, will suck it and see how it performs.



Got an idle up switch coming from stormforce, going to re label it LockUp
and mount in centre console with active lamp just above it.
All i need to do is thieve, i mean source some 5pin relays and of course make
it look all neat and tidy and obviously take some pics as i go.

Oh and find the Solenoid 2 feed from the ECU.......

[gwh200]

A bit of R&D for sure... I'm intrigued as to how these aregoing to perform.. This is a real interesting notion. Do post up how it performs.

[Paul1566]

Being a big girls blouse and needing an ohshit button has me thinking...
Can i use diodes to allow more than one input to the unlock relay ?
I know i could just put the panic button in the 0v line and break the loop
but if in future i wanted to use a signal from a live source would this work ?



I am trying to keep it simple and easy for anyone with a soldering iron to follow, so no IC's or transistors involved.....

[dieselboy]

How did this go? I am after doing this to mine for many reasons. People with a 2.4 would benefit more I feel.
Did you complete this? I'm thinking about just a simple switch on/off for the moment with mine, and can wire in extras later.