Where to Buy Timed Relay/Switch
Submitted: Thursday, Apr 07, 2016 at 11:43
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garrycol
My small cubby fridge in my centre console runs on straight 12v and I have accidently left it on a couple of times with a flat battery resulting.
I could change it to switched 12v but that means it will be off whenever the ignition is not on. Likewise I could use a voltage cutout switch but this means that the fridge could stay on for a long time before switching off and am not keen on this and would like greater control.
The ideal is a relay that has 12v and switched 12v and inbuilt timer so that when switched 12v is turned off the unit continues to run on the 12v for the set time before switching off.
I have seen these listed overseas but I have not found nothing here. I have checked Jaycar and they do not any but have a straight on/off timer but that is not what I am looking for.
As you can see I am aware of other options but looking at my preferred one first.
Any ideas on where to buy this type of relay??
Thanks
Garry
Reply By: Malcom M - Friday, Apr 08, 2016 at 06:40
Friday, Apr 08, 2016 at 06:40
Is this what you want to do?
1/ power on car and fridge powers up at the same time
2/ power off car but fridge continues to run for xx minutes then switches off
You are not likely to find that off the shelf as it will require some rewiring of the vehicle.
The idea is simple enough but you need a 12v ignition feed plus a 12v battery direct feed.
HKB's module ill likely do the job in mode 5 or 6 along with some rewiring.
AnswerID:
598335
Follow Up By: vk1dx - Friday, Apr 08, 2016 at 07:46
Friday, Apr 08, 2016 at 07:46
I don't think that the car wiring needs to be changed Malcom. But the module and a few components would have to be installed safely in a box between both the accessory +12 and the car's 12V "allways on" power. The trick is to get a pulse to indicate that the car has been turned on. A simple electrolytic cap, with or without a resistor, on the accessory line would do that. The standard module would then work as is. Not sure about which mode though.
But not a job for a novice and maybe even some auto electricians would find it hard to get their heads around.
Phil
FollowupID:
867514
Reply By: vk1dx - Friday, Apr 08, 2016 at 07:59
Friday, Apr 08, 2016 at 07:59
Garry
I have posted a few words above but am puzzled why you need this setup. We installed an additional battery and a Redarc isolator under the bonnet to supply power for all 4wd and
camping accessories, including
camp lighting, driving and fog lights. Why not do the same with your console fridge. The Redarc isolator will protect the crank for you. Maybe a small 12 V battery from a small car or motorbike (are they 12V) and the small isolator. Then you have power for other small accessories down the track. Maybe even put the CB on the circuit.
If you take a battery to the bush in the car then you would have to do this anyway.
Personally, if I was going to be away from the car for a long time, then I would turn the fridge off. This is what a lot of us do with the CB when power directly from the battery.
Phil
AnswerID:
598338
Follow Up By: garrycol - Friday, Apr 08, 2016 at 10:51
Friday, Apr 08, 2016 at 10:51
Thanks Phil - I dont have a second battery or isolator - this is the OEM fridge in the center console - has a simple switch to turn on and off and a few times I have left it on and flattened the battery a couple of times.
From the responses it would seem what I am after does not exist locally as a single unit so I will most likely put in a low voltage cutout and continue to turn it on and off manually and if I forget, the low voltage cutout will come in to play.
Cheers
FollowupID:
867525
Follow Up By: vk1dx - Friday, Apr 08, 2016 at 11:07
Friday, Apr 08, 2016 at 11:07
I was wondering if the user handbook has any ideas or hints.
Phil
FollowupID:
867526
Follow Up By: garrycol - Friday, Apr 08, 2016 at 13:44
Friday, Apr 08, 2016 at 13:44
The car handbook just says to switch the unit on when needed and switch off when not needed and a warning that leaving it on without the engine running may result in a flat battery.
However the relay that Grizzle linked to above seems to be what I wanted so I will print that page and see if Ashdowns or other car electronic specialists can supply.
Cheers
Garry
FollowupID:
867531
Follow Up By: Member - ACD 1 - Friday, Apr 08, 2016 at 14:10
Friday, Apr 08, 2016 at 14:10
Finally!
A Vehicle User Manual that has simple to follow and accurate information.
Sorry Gary, I just loved your description and couldn't let it go past.
If a constant on supply is needed to trigger the timer, it won't be hard to find - usually one of the wires into the clock, radio etc will be constant to supply the memory.
Cheers
Anthony
FollowupID:
867533
Follow Up By: garrycol - Saturday, Apr 09, 2016 at 20:11
Saturday, Apr 09, 2016 at 20:11
Yes wiring is not such an issue - piggy back fuse on the main fuse box will do the trick.
FollowupID:
867579
Follow Up By: vk1dx - Saturday, Apr 09, 2016 at 20:52
Saturday, Apr 09, 2016 at 20:52
See my post below.
FollowupID:
867582
Reply By: vk1dx - Saturday, Apr 09, 2016 at 21:00
Saturday, Apr 09, 2016 at 21:00
This may be abit of overkill for just one circuit but it allows for easy expansion and extra ccts in the future. And makes fault finding 100% easier. You don't have to climb around the car looking for the fuse.
I put one in my car for all accessories such as lights,
camp lighting, fridges, radio etc. I also mounted some relays nearby for driving and fog lights and a spare.
From Jaycar, 100 max with 10 ccts at 30 amp max each one. Fused as you wish.
Phil
AnswerID:
598422