Voltage Regulator
- Thread starter Buzznitro
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- led interior lights
Depending what strip, when an led is rated at 12v, it is just that, any more or any less will damage it. Your van has the potential to get to over 14.5v. A driver can also be known as a regulator, its the bit that feeds the led power - just fancy talk lol
Most automotive leds will be rated at 9 to 32v, sounds like yours may not be automotive, so needs a voltage reg to keep a fixed 12v regardless of the vans fluctuating voltage. Don't get me wrong they will turn on & work but it will be damaging to them, they may last a minute, an hour or a year but not as long as they should
Just for info, leds don't dim if the voltage goes down, as said this damages them, they dim on frequency. Imagine switching a switch on really quick, this will cause the light output to be different to it switched slowly. Have you wondered why when filming a car with led lights they seem to flash or flicker, that's the frequency doing its thing, this is called pwm (pulse width modulation) we are talking 1000's times per second so don't try this with a normal on/off switch lol. Not all leds will dim either.
Hope that's clear as mud lol.
Most automotive leds will be rated at 9 to 32v, sounds like yours may not be automotive, so needs a voltage reg to keep a fixed 12v regardless of the vans fluctuating voltage. Don't get me wrong they will turn on & work but it will be damaging to them, they may last a minute, an hour or a year but not as long as they should
Just for info, leds don't dim if the voltage goes down, as said this damages them, they dim on frequency. Imagine switching a switch on really quick, this will cause the light output to be different to it switched slowly. Have you wondered why when filming a car with led lights they seem to flash or flicker, that's the frequency doing its thing, this is called pwm (pulse width modulation) we are talking 1000's times per second so don't try this with a normal on/off switch lol. Not all leds will dim either.
Hope that's clear as mud lol.
As above. The power draw of a "pure" LED (without any regulation) goes up exponentially by the voltage which eventually would turn the LED quite hot as all the power fed in has to be dissipated somehow.
An example of a basic LED characteristics from site https://www.electronics-tutorials.ws/diode/diode_8.html
And turning the above into practice of a pure "12V/10W" LED element (without built-in regulator):
11.8 V --> 0.8 A (the nominal working point for this one, total power to dissipate about 10W, part of that radiated as light but still remaining losses heat the back plate eventually up to 60C (when at free space at 20C).
So a kind of bottom line is that going only 0.4 Volts (11.8V -> 12.2V) above the nominal voltage already doubles the power (so also the losses-->heat).
When engine/alternator is running the voltage reaches maximum of about 14.8 Volts. Didn't have the courage to go that high as anything above the nominal heats up the element a lot and quick.
PS. Actually the LED element above is sold as "12V/16W" which is what it exactly does but I'm not quite comfortable running it long times at that level so I have used a standard 10W driver which limits the current a bit (and handles full voltage range) and thus keeps the temperature at more acceptable level (without extra heat sink).
An example of a basic LED characteristics from site https://www.electronics-tutorials.ws/diode/diode_8.html
And turning the above into practice of a pure "12V/10W" LED element (without built-in regulator):
11.8 V --> 0.8 A (the nominal working point for this one, total power to dissipate about 10W, part of that radiated as light but still remaining losses heat the back plate eventually up to 60C (when at free space at 20C).
So a kind of bottom line is that going only 0.4 Volts (11.8V -> 12.2V) above the nominal voltage already doubles the power (so also the losses-->heat).
When engine/alternator is running the voltage reaches maximum of about 14.8 Volts. Didn't have the courage to go that high as anything above the nominal heats up the element a lot and quick.
PS. Actually the LED element above is sold as "12V/16W" which is what it exactly does but I'm not quite comfortable running it long times at that level so I have used a standard 10W driver which limits the current a bit (and handles full voltage range) and thus keeps the temperature at more acceptable level (without extra heat sink).
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If they are powered from your leisure battery, and you have a DC to DC charger, then they won’t see the 15 volts that they would if they were powered from the van battery.
In my experience you will need some sort of dimmer (we use CBE) as they could be much too bright in the evening/night inside the van.
Where will they be mounted ?
Pete
In my experience you will need some sort of dimmer (we use CBE) as they could be much too bright in the evening/night inside the van.
Where will they be mounted ?
Pete
It will look good, but if they get the full voltage from your leisure battery then they could be too bright. This may be why your electrician is recommending a regulator/dimmer of some sort.
We have 12 lights in our camper roof (no pop top). They are controlled through a pair of CBE dimmers, and to be honest they are rarely on any more than the minimum setting in the evening.
Pete
We have 12 lights in our camper roof (no pop top). They are controlled through a pair of CBE dimmers, and to be honest they are rarely on any more than the minimum setting in the evening.
Pete
Hmmm... if they were LEDs without built-in regulator/driver, the answer would be yes - each separately, but as you then mention
it sounds that they have built-in regulator and thus could be fed directly from any supply. I guess you should look what's the voltage spec on the light - if it has a range (e.g. 11-15 Volts) that definitely means a regulated "ready-to-use" unit.
