That light that comes on when you open the door.....

[EdRedBird]

So ... I am wiring up .... I do not have my house batteries yet so I am using the existing wiring as a powersource
What I mean is that I disconnected the two lights in the back of the van and use that as a powersource temporarely

So I go from whatever you call these lights that magically switch on and off or powersource for them switch box ...and can test functionality of one switch at a time. Once I have the batteries it will go to a fusebox and these batteries

So these lights are on when i turn the ignition off ... and after x ammount of time the lights go off by magic
The same when I open the door .... poof ... untill i start the engine and they are gone again

Handy feature it does not drain your battery

IS it possible to give a light 2 powersources? without 1 battery "bleeding/leaking into the other?
Or ending up with 24V spikes

So I can drive ..park up in the pissing rain..rotate my chair and get up (there is an unbuckle there as well somewhere) ...with inside lights on.... and switch on the house battery power to this battery before it miraculously shuts down

autorouter I presume the magic is capacitor based?

 

[bridgedino]

Eh

 

[Richard n Ann]

@autorouter I presume the magic is capacitor based?

The site knowledge bot will be along shortly

 

[mitzimad]

lights now days are controlled by a controller rather than a switch

 

[Andacami]

To save an accident, a diode or two maybe is what you need? But trying to decipher what you want/mean and why is a bit difficult.

^{_{Subscribers  do not see these advertisements}}

 

[autorouter]

I presume the magic is capacitor based?

I very much doubt that. When I first started in electronics it was all valves, heater supplies and high voltage DC. Then it was transistors, and analogue circuits with capacitors and resistors. Now it's cheaper to use a microchip with digital timers and relay drivers.

For the switching, you could use a changeover switch (also called a 2-way switch) with the light connected to the 'COMMON', and the two batteries connected to the other two terminals. To turn the light off, switch it back to the starter battery, which will be off because the time switch will have timed out. In the product lists they are often called 'Single Pole Double Throw' or SPDT.

Some switches are 'Make Before Break', where the two circuits are momentarily connected as the switch operates. This is to avoid the very short break while switching circuits. Since the two batteries are both 12V, and both reasonably charged, then connecting them together momentarily is unlikely to be a problem. Other switches are 'Break Before Make', where one circuit is definitely disconnected before the other is connected. There will be a momentary flicker of the light. I'd suggest a Break Before Make type if you have a choice.

 

[EdRedBird]

To save an accident, a diode or two maybe is what you need? But trying to decipher what you want/mean and why is a bit difficult.

I find it hard to explain
That light that temporarely comes on when you open the door .... (or shut down the engine)
Is there a way to wire this to the house battery, power it continiously ...without house battery leaking into "car battery"
So:
As soon as i park the car I have 30s -1 min light to reach the switch to permanently turn on the light

 

[EdRedBird]

For the switching, you could use a changeover switch (also called a 2-way switch) with the light connected to the 'COMMON', and the two batteries connected to the other two terminals. To turn the light off, switch it back to the starter battery, which will be off because the time switch will have timed out. In the product lists they are often called 'Single Pole Double Throw' or SPDT.

And right at 2 way switch I went Doh....
I should have thought about that... so simple but yet elegant

 

[Ian Bosman]

I very much doubt that. When I first started in electronics it was all valves, heater supplies and high voltage DC. Then it was transistors, and analogue circuits with capacitors and resistors. Now it's cheaper to use a microchip with digital timers and relay drivers.

For the switching, you could use a changeover switch (also called a 2-way switch) with the light connected to the 'COMMON', and the two batteries connected to the other two terminals. To turn the light off, switch it back to the starter battery, which will be off because the time switch will have timed out. In the product lists they are often called 'Single Pole Double Throw' or SPDT.

Some switches are 'Make Before Break', where the two circuits are momentarily connected as the switch operates. This is to avoid the very short break while switching circuits. Since the two batteries are both 12V, and both reasonably charged, then connecting them together momentarily is unlikely to be a problem. Other switches are 'Break Before Make', where one circuit is definitely disconnected before the other is connected. There will be a momentary flicker of the light. I'd suggest a Break Before Make type if you have a choice.

IK would agree, the Make before type can, if they have an internal fault, lead to the two batteries together feeding the light. Switches are mechanical devices generally so subject to wear and tear.