12v light delay question

[brodders97]

Hi all,

I’m doing my bathroom up currently and in the process, I want to look at the delay in one of the lights

3x downlights are 230v, one is 12v as it’s got an Integrated fan.

I know the couple second delay is due to the voltage dropping to 12v, but is there any way to eradicate this? It’s really annoying when you walk in, then turn the lights on to have 3 come on and one come on later.

Thanks

 

[pc1966]

Some LED lights are like that, not sure why. Only option is to look at replacing the lamp (assuming it is replaceable) as you might find they vary from light to light in the same basic model (we have ne 50W flood that comes on a second late).

Only other thing is to look at replacing that unit with some other model to see if it is quicker, but I doubt that is value for money.

 

[brodders97]

Some LED lights are like that, not sure why. Only option is to look at replacing the lamp (assuming it is replaceable) as you might find they vary from light to light in the same basic model (we have ne 50W flood that comes on a second late).

Only other thing is to look at replacing that unit with some other model to see if it is quicker, but I doubt that is value for money.

Thanks for your reply, I recently got another 12v bulb to put in it, same issue. I was wondering if it was something to do with the power the bulb is compared to the transformer? I have no clue

 

[pc1966]

Thanks for your reply, I recently got another 12v bulb to put in it, same issue. I was wondering if it was something to do with the power the bulb is compared to the transformer? I have no clue

Sounds like the "transformer" feeding it is slow to come on. Typically these days they are not transformers as such, but switch mode AC-DC converters like PC power supplies, etc.

I have no idea if that is a separate unit and/or if a replacement would cure things to your satisfaction. It might, but equally it might be a waste of money is they simply are all like that.

 

[brodders97]

Sounds like the "transformer" feeding it is slow to come on. Typically these days they are not transformers as such, but switch mode AC-DC converters like PC power supplies, etc.

I have no idea if that is a separate unit and/or if a replacement would cure things to your satisfaction. It might, but equally it might be a waste of money is they simply are all like that.

Thanks again, I’ll see if I can do something with that, have a good weekend

 

[pc1966]

Just to confirm, all are LED lights? It is not a halogen one in the fan unit?

 

[brodders97]

Just to confirm, all are LED lights? It is not a halogen one in the fan unit?

3x are led, one was halogen originally which got replaced with led. Now it has the issue

 

[pc1966]

3x are led, one was halogen originally which got replaced with led. Now it has the issue

Interesting. Did you try a different brand of LED replacement when you tried replacing it?

 

[brodders97]

Interesting. Did you try a different brand of LED replacement when you tried replacing it?

I have yeah, I actually think 3 in total. First one was a cheap one I had lying around, second was from Screwfix can’t remember the brand. Third was by integral led

 

[pc1966]

I have yeah, I actually think 3 in total. First one was a cheap one I had lying around, second was from Screwfix can’t remember the brand. Third was by integral led

Drat.

Back to halogen?

 

[brodders97]

Drat.

Back to halogen?

May be an option. Just a quick one, I’ve been in the loft. The led is fed by a separate led driver. The led driver was 30W. As there’s no halogen it doesn’t need to be that big. So I swapped it for a 5W 12v driver.

The delay is now even longer. Do you think I need to go for a higher powered driver?

 

[pc1966]

May be an option. Just a quick one, I’ve been in the loft. The led is fed by a separate led driver. The led driver was 30W. As there’s no halogen it doesn’t need to be that big. So I swapped it for a 5W 12v driver.

The delay is now even longer. Do you think I need to go for a higher powered driver?

It is unlikely to be as simple as just the power level of the driver. My own bathroom as IP65 lights with separate driver that is only 10W or so and they are more or less instant on.

Sadly specifications like turn-on time are rarely given

 

[brodders97]

It is unlikely to be as simple as just the power level of the driver. My own bathroom as IP65 lights with separate driver that is only 10W or so and they are more or less instant on.

Sadly specifications like turn-on time are rarely given

That’s a shame, so much for being energy efficient. Thank you for your help

 

[marconi]

It may be the integrated fan and lamp fitting is a safety electrical low voltage SELV type operating from a special separate safe mains to SELV 12V power supply.
Both the fan motor and lamp are energised from the same power supply. If this is the case then during the start and run up to speed of the motor the so called starting surge current will depress the output voltage of the power supply. Only when the motor is running at speed is the output voltage sufficiently back to normal 12volts for the halogen or led to draw enough current for them to illuminate. Both types of lamp also have there own short period when they draw more current than there rated running current. The delay in lighting the lamp is due then to the motor start up surge and then the surge period for the lamp.

Solution - separate SELV 12V supplies of suitable power for fan and lamp (preferred) or one more powerful regulated SELV power supply for both (may or may not eradicate delay). But then you would be modifying a bought product designed to be safe which opens up a minefield of safety issues.

Post details of the integrated fan and lamp.

ps: led lamps have minimum voltage requirements too.

 

[pc1966]

Both the fan motor and lamp are energised from the same power supply. If this is the case then during the start and run up to speed of the motor the so called starting surge current will depress the output voltage of the power

Brilliant thinking!