Overdrive Warning Device

[Stu 1986]

Hello Chaps,
I was musing over Herald matters this morning whilst drinking my coffee and I begun to think about an "Overdrive On" warning device. I checked out what others had done and I've seen a wide array of warning lights. But I wondered if it might be possible to also fit a buzzer? The idea being it would sound if I were to leave the O\D engaged and move the selector away from 3rd & 4th. We have a similar thing fitted on some of the buses that warn us the doors are open with the handbrake off.

Anyone have any ideas what would need to be done to achieve this? Its just a little idea I had.

Thanks
S.  

[Dannyb]

Hi Stu,
I wrote an article in last month's mag about fitting O/D warning light into the gear knob. Fitting a buzzer, that's a thought, probably have to incorporate a relay in the circuit.

[Ridgetone Triumph]

What a useful idea, I could have one for the lights too. I have got so used to sitting in the modern jobs and letting them do all the work, that when I get into the Triumph I forget how to drive it.......Well actually reverse it, switch on and off the lights, and park it  

[Nick Moore]

Generally the car will give you a gentle tap on the nose with the steering wheel if you change from third overdrive to second. After a surprisingly short time (in my case less than twenty years) you learn not to do it.

[Andy Flexney]

take it as a challenge to learn to master these cars instead of trying to change them into moderns.

AndyF

[Hogie]

Hi Andy,
             yours is the best simplest idea.

Hi Stu,
          you could buy an OD logic box that will take you out of OD each time you change gear (and more). The ones on the market are about £70 but can be knocked up for about £10 - I've done this on my 4A.

Hi Ridgetone,
                   the lights is easy - one relay, one LED, a buzzer and two wires. One wire to the lighting circuit, one wire to ignition.
The Ig goes to the relay coil, the light circuit goes to one of the contacts - these are Normally Closed NC - the other contact goes to a buzzer then earth.
With ig on the relay is open circuit - buzzer off.
With Ig off and light on the relay is closed and the buzzer buzzes. Turn lights off buzzer stops.
You could incorporate a switch (or timer) to over ride the circuit.

Roger

[JohnD]

A buzzer, to sound when you changeout of overdrive?
To remind you of what you just did?
And then stops?
Is this Altsheimer's Week?

A light to glow all the time that you have the overdrive switch turned on, Yes.
I mounted  a  switch on my steering wheel, as I could not be bothered to source an OD steering binnacle switch, and the gear stick switches rely on hair-thin wires inside the stick.
It's a 'press-on, press-off' switch, and I put a little LED beside it that is ON when the switch is ON.
In this application, you need a curley-whirley wire from dash to steering wheel.
If that works in BTCC, it'll work for me.
You may not like it, but the same LED that stays on when the switch is on is 'Simples'.

John

[WIMPUS]

I use my Spit as a daily car.

A buzzer for when the switch is still in OD and you are not in 3th or 4th .. i would say no.
But a light on the dash, that i probably going to do when i put the new OD in. 🙂

Like Roy did with his GT6 ..
https://www.youtube.com/watch?v=ot1SuR_9inw

[Clive]

Quoted from Spitfire6

Hi,
I also see no need for an OD light.
But if you wanted to do this;
Buy a solid-state buzzer and connect the + to ignition live.
Connect a capacitor to the negative terminal of the buzzer.
Connect other end of capacitor to solenoid.

Every time the solenoid is switched off the buzzer will sound.
Duration of sound will be adjusted by capacitance value you pick.

That's the cheapest/simplest/easiest way to achieve what you want.

A better way would involve a micro and quite a few lines of code(difficult). A Micro programmable chip will cost about a quid. A micro would also allow you to do much, much, much more.. Something I was working upon a long time ago.

Cheers,
Iain.

but that will sound even if you just switch the od out without changing gear or whatever.
to get it to only buzz when the switch is "in" but the inhibitor switch is "out" is impossible without some serious changes.

Nope, just get used to it, it really isn't a long learning process to get it right 95% of the time, and a buzzer wont get on your nerves. If you could hear a buzzer in a herald!

[Stu 1986]

Quoted from AndyF

take it as a challenge to learn to master these cars instead of trying to change them into moderns.

AndyF

I appreciate what you're saying, and I'm not trying to make it modern either. I'm trying to save myself making a potentially expensive mistake. I've just paid a man in Coventry £500 to rebuild my gearbox, which to me is a lot of money. I don't want to have to do this again so anything that can help prevent this I'm game for. Some of the trucks I drive have buzzers built in to let you know you've moved to low range of have the diff locks in.

I'm not 100% sure how the system functions on these cars, but I imagine the O/D would stay on if you moved out of 3rd to 2nd without disengaging the O/D. My idea was to have the buzzer sound if you did do this, somehow using the O/D sensor on the box?

These warning buzzers aren't modern ideas either, my friend's 1956 Chevrolet Buzzes if you leave the lights on.

[esxefi]

no,if you have the inhibitor switches which are standard then the o/d will switch out automatically for the very reason of driveline protection.
if you have a j type they can take a fair bit of abuse anyway,mine had some punishment on the drag strip and it was the normal clutch that went first the o/d was fine.

you could just look at the switch to see if it is in or out.

[ferny]

As to headlight warning buzzers - I fitted one to the acclaim, powered by the sidelights and earthed on the door switch. Open the doors when the lights are on and the buzzer sounds.

[RobPearce]

I don't get all this talk of relays and micros, nor even capacitors. What the OP wanted was a buzzer to sound when the overdrive has been left "on" but isn't actually on because the gear lever is in second. So this is the condition where the circuit to the solenoid is "made" at the control switch, fed with live by the ignition, but is "broken" at the inhibitor. If you want your buzzer to sound in this condition, and this condition only, you simply wire it across the inhibitor switch.
Turning off the ignition removes power - no noise.
Turning off the overdrive switch cuts the circuit to the buzzer - no noise.
Putting the gearbox back into third shorts the buzzer out - no noise.

[Clive]

Rob, I thought of that, but it would be earthing via the solenoid. I (maybe too quickly) dismissed it on those grounds, not sure what the resistance is of the solenoids. But thinking about it probably in the range less than an ohm to 4 ohms? J types use a high momentary current to engage, d types more consistent. So may just work.

Think teh OP needs to check the inhibitor switch is actually there, check to see if OD works in 2nd gear that should do the trick.

[Stu 1986]

I've got a D-Type overdrive fitted to mine, it's got the inhibitor switch on there which itself was refurbished when the box was rebuilt. If the OD disengages itself when I move to 2nd then that's great and I needn't worry about fitting a buzzer. I didn't know that's how it worked, so I've learned something new.

Thanks For All the advice and replies.

[RobPearce]

Quoted from cliftyhanger

Rob, I thought of that, but it would be earthing via the solenoid. I (maybe too quickly) dismissed it on those grounds, not sure what the resistance is of the solenoids.

The D-type solenoid draws 2A hold current when engaged (much more when first energised) but is driven through a relay. The J-type draws a few amps. A 12V buzzer will probably pass 250mA - way too little to have any effect on the solenoid. Some care would be needed on a D-type setup because you're driving the relay coil, which is rather lower current. In that case I'd probably suggest a high efficiency red LED instead - with suitable resistor, it will only pass 10mA.

[Clive]

Oops, re-reading my post I got the od's the wrong way round!
LED would be much better as a warning device, it has got me thinking now. I have 2 co-drivers for the RBRR who have never driven an OD equipped car. However, they are not daft (he says, crossing his fingers!)

[Jonny-Jimbo]

I have a few neat chrome toggle switches that have an LED built into the end, saves the need for fitting a light as well as a switch, which I have on my electric cooling fan, and will have on my electric fuel pump when that's fitted and sorted out... Quite cheap, and feel to be good quality, from Vehicle Wiring Products.

Obviously, if you're going with an original switch, my suggestion doesn't help at all.

You could just get in the habit of pushing the switch as you go to change gear anyway so you know the OD is always disengaged when changing gear?