Thread Starter

Selvedin

Joined Jan 25, 2021
21
Hello good people,

I bought a car ambient light neon strip.
It works with an adapter which transforms DC voltage to about 100V AC.
When I test it on my adapter it works just fine, it shines perfectly at 6V and 12V.
The problem is when I connect it to the windows up/down light at the cars door (where it needs to be connected).
The voltage there is from 3V to 9V (depending how bright you set the ambient light in the car).
After connecting, the neon strip and the windows up/down light start to flash.
I don't know what it could be, I tested it with 4 adapters and 4 light strips, everytime the same, have you an idea?

Greetings.
 

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MisterBill2

Joined Jan 23, 2018
8,761
The pictures provide us with no useful information towards solving your problem. And the intention of the installation is not clear, either.
The one thing that appears to be obvious is that the power available at the point you have connected the neon light strip is not what it needs for correct operation. Probably the current capability is not adequate for the additional load, and certainly the voltage is not right, as a result of the additional current required for the neon light device.
So you will need to power this additional light from a different connection point that will provide adequate power.
 

Thread Starter

Selvedin

Joined Jan 25, 2021
21
This was my first thought too. That the current is to weak.
But now I have installed it on the two rear doors.
When it was just on one door, it blinked about 2x in 10sec, now when I installed a second one, it still has the same flickering time, still about 2x in 10sec, shouldn't it blink more often when 2 loads are installed? Considering the fact that it all comes from the same power supply, same fuse...
 

MisterBill2

Joined Jan 23, 2018
8,761
Even in an old vehicle like my work van, the accessory loads are controlled by the body control computer. So what happens when the load increases is determined by the software, not any logical function.. Evidently that software has decided that the additional load is excessive. And I am still wondering about the purpose of the additional lights. That is a bit unclear to me.
 

BobTPH

Joined Jun 5, 2013
3,315
The point you are connecting to is not intended ti provide power to something else. From your description it is probably a PWM source with a resistor in series designed to power an LED..

A circuit could be used to take this signal and use it to control power to the inverter from an appropriate 12V power source, but that requires active electronics.

Bob
 

MisterBill2

Joined Jan 23, 2018
8,761
The point you are connecting to is not intended ti provide power to something else. From your description it is probably a PWM source with a resistor in series designed to power an LED..

A circuit could be used to take this signal and use it to control power to the inverter from an appropriate 12V power source, but that requires active electronics.

Bob
Why use an inverter to provide 12 volt power in a 12 volt car? A transistor driving a relay would be quite adequate.
 

Thread Starter

Selvedin

Joined Jan 25, 2021
21
I think he wants the light to come on when some other light comes on.

Bon
Yes, I want to use the power from the existing door light, because the brightness of that can be controlled and it is recommended to connect it there.
I am only confused, because no matter if the brightness is on min or max, it still flashes and it flashes in different time periods. Let's say, in 10sec it flashes 1x but sometimes 5x.
Can this be fixed by soldering a capacitor, which will provide energy when it shuts down?
 

MisterBill2

Joined Jan 23, 2018
8,761
The point you are connecting to is not intended ti provide power to something else. From your description it is probably a PWM source with a resistor in series designed to power an LED..

A circuit could be used to take this signal and use it to control power to the inverter from an appropriate 12V power source, but that requires active electronics.

Bob
Bob is right, it is not a matter of simply filtering. First, the existing connection is not able to provide enough power. Further, we have no idea about themechanism of control used to dim the present light. And now I am wondering how that relates to the window up/down light circuit mentioned in the first post.
 

Alec_t

Joined Sep 17, 2013
12,070
I want to use the power from the existing door light, because the brightness of that can be controlled
In this day and age it's almost certainly controlled by the car body MCU using PWM. A capacitor across the ambient light device supply terminals might solve the problem; on the other hand it might upset/confuse the MCU if/when it does diagnostic checks at start-up.
 

MisterBill2

Joined Jan 23, 2018
8,761
If the existing light load is quite low, it is very probable that the driver is not able to provide that much additional power. And adding a capacitor across a PWM line may cause some expensive damage to that control module.
I suggest a separate dimmer power connection for the added light installation.
 
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