CanBus Switching from a Reversing Bleeper Circuit?

[RedDiesel Burner]

On a New Farm Telehandler the Revesing Bleeper is pulse Bleeped via the wiring ok.
all CANBUS so i believe.
I would like a trigger feed to activate a sep Relay to power Reversing Lights as such
yes it doesnt have any.
Is there such a circuit or box available that i could add in somehow to be switched to a perm live state
when the bleeper circuit is live & pulsing & when the pulsing stops it switches the Box off?
Many Thanks

 

[kellys_eye]

A retriggerable monostable circuit will do it. Pick the timing components to exceed the pulse period of the sounder and use the output to drive a light.

https://www.automation24.co.uk/anal...reviewPriceListId=1&refID=adwords_shopping_UK

 

[RedDiesel Burner]

wowzers thanks so how do i go about wiring such a component up exactly? i see the part on your link
but have no idea of how to fit this in as such. how do i know where to set them adjustments on it also?
Thanks

 

[John Canon]

I will try to explain with words so I don't have to draw a diagram: Is your machine 12 or 24 volts? That linked timer says 120 or 240 volts AC, so you might have to look for a different timer. A timer needs its power voltage and a trigger voltage. The trigger voltage (from the beeper) is probably sharing a common ground with the power voltage,

Retriggerable is definitely what you need, that means you can trigger the timer (turn it on) again before the initial countdown is finished. So the intermittent beeper pulse keeps the timer on, then the timer will turn off a few seconds after the last beep. Once you have the timer voltage and beeper pulse voltage figured, then you look at the output relay contacts on the timer. The NO normally open contact is just like a light switch ... it turns ON and OFF whatever is wired in line with it, So you take tap off your power voltage, run it through the output contact, then on to the lights. Of course you will add a fuse in the power circuit.

Find a timer with the correct supply voltage, and read the instructions fully. Find the drawing that matches your needs, then re-draw it to match your setup exactly. Plan your locations and wiring. Maybe put together a test circuit and see if the pulse actuates the output relay. If the beeper goes once per second, then set the timer for 2 seconds. Be sure the timer is set for DELAY-OFF operation. That way it turns ON when triggered, and turns OFF after the trigger is gone. Good luck!

 

[Kiwi]

Have you checked if the power supply to the beeper is pulsed or constant?
The beeper may have internal circuitry to make the pulsed sound.

 

[RedDiesel Burner]

I will try to explain with words so I don't have to draw a diagram: Is your machine 12 or 24 volts? That linked timer says 120 or 240 volts AC, so you might have to look for a different timer. A timer needs its power voltage and a trigger voltage. The trigger voltage (from the beeper) is probably sharing a common ground with the power voltage,

Retriggerable is definitely what you need, that means you can trigger the timer (turn it on) again before the initial countdown is finished. So the intermittent beeper pulse keeps the timer on, then the timer will turn off a few seconds after the last beep. Once you have the timer voltage and beeper pulse voltage figured, then you look at the output relay contacts on the timer. The NO normally open contact is just like a light switch ... it turns ON and OFF whatever is wired in line with it, So you take tap off your power voltage, run it through the output contact, then on to the lights. Of course you will add a fuse in the power circuit.

Find a timer with the correct supply voltage, and read the instructions fully. Find the drawing that matches your needs, then re-draw it to match your setup exactly. Plan your locations and wiring. Maybe put together a test circuit and see if the pulse actuates the output relay. If the beeper goes once per second, then set the timer for 2 seconds. Be sure the timer is set for DELAY-OFF operation. That way it turns ON when triggered, and turns OFF after the trigger is gone. Good luck!

Hi My Machine a MERLO Telehandler is all 12v
is there no such thing i can buy thats made to do this task without having a electronics A Level degree to make something from scratch
i can solder & stuff but my limited knowledge of building a complex circuit is beyond me !
Thanks

 

[RedDiesel Burner]

Have you checked if the power supply to the beeper is pulsed or constant?
The beeper may have internal circuitry to make the pulsed sound.

Deffo pulsed from supplying circuit as the dealer i had a demo machine from had a small led worklight on same circuit & all it did was flash everytime the reversing bleeper BLEEPED!!

 

[RedDiesel Burner]

Just to add the circuit to the bleeper is perm live & no idea how canbus does what it does but when you select revese the beeper squaks on/off

 

[John Canon]

The canbus is the digital signals talking between the various modules. It is the module that puts out the "beep signal" to the beeper. We want to use the 12 volt signal that goes to the beeper, nothing to do with the canbus. As you learned, any light connected across the beeper will flash whenever the beeper beeps. What the timer does is keep that voltage going long enough to light a bulb.

This timer https://www.amazon.com/Altronix-6062-Digital-Timer/dp/B0006TZEDS is all you need. They are versatile timers that can do just about anything. I have used them many times. As I have said it has a trigger input, a relay contact output, and a supply voltage to power the timer. It is basically 5 wires, a couple of setting switches, and a turn control for the number of seconds. On the vehicle you need access to the beeper wire, a hot-on-ignition wire, and a ground point on body or frame. I can draw a diagram once you have the timer and checked a couple of things on the vehicle.

If you know a local alarm installer or electrician, they could probably do the job right away. Or check back here once you have the timer. It is no more difficult than loosening your power steering pump and changing the valve cover gasket. Except it's electronical... haha.

 

[John Canon]

This is a time delay relay that I would use. https://www.summitracing.com/parts/hla-996152131

 

[Kiwi]

The Hella 996152131 timer relay would be a good choice, provided the beeper has a constant ground.
The beeper would have to have the positive pulsed to work with this relay. Won't work if the beeper negative is pulsed.
See diagram below.
30 - fused 12v battery or ignition supply
31 - ground
15 - pulsed positive to beeper
87 - output to reverse lights

Operation.
When the beeper is pulsed on, the relay will latch on connecting 30 to 87. This will turn the reverse lights on.
The relay will remain on when the beeper pulses off. Reverse lights stay on.
The relay delay time will be reset when the beeper is pulsed on again.
The reverse lights will remain on as the beeper pulses on and off.
The relay delay time setting just has to be set slightly longer than the beeper off time.
Once the beeper stops beeping, the relay will time out and the reverse lights will go off.

A "cheap and dirty" option might be to connect a capacitor across the coil of a standard mini relay.
The coil would be connected across the beeper through a diode(1N 4007).
Would be trial and error to find the correct size capacitor to get the desired time delay.

 

[RedDiesel Burner]

Good info this everyone big thanks
iam assuming its got a perm ground.
Maybes if i put a meter on wiring when machine is switched off & see if either wire links back directly to chassis eh.
Merlo UK just refer me to my Dealer when ive asked them & Dealer pretty much gives up on the idea when ive asked them about it

 

[Kiwi]

Don't assume that there is a ground. Test to make sure.

Can the dealer advise if reverse lights are an option?

I haven't worked on a Merlo for ages and don't know anyone at the local dealer, so unfortunately I can't get any info on their wiring.

 

[RedDiesel Burner]

Dealer isnt much help ive asked several times & gave up.
So if this CANBUS wiring is a switched Negative or pulsed Negative whats my options then?
I'll get a meter on it hopefully at some point on sunday & report back.
Its weird its just perm 12v across the two wires atm i remember that
I have a reversing camera to wire up & it can be activated so it only comes in in reverse but i tried a link from the cameras power only to find it was live all the time also