What does a "self-ballasted" LED mean ?

Could some electronics guru pleas explain what 
a "self-ballasted" LED lamp mean ? I have seen
LED lamps, running off the AC line, and powered
by a simple small 5V 1 Amp SMPS, but what exactly
does a self-ballasted LED lamp mean ?

On 11/19/2014 8:40 PM, dakupoto@gmail.com wrote:
> Could some electronics guru pleas explain what
> a "self-ballasted" LED lamp mean ? I have seen
> LED lamps, running off the AC line, and powered
> by a simple small 5V 1 Amp SMPS, but what exactly
> does a self-ballasted LED lamp mean ?

built in current limit???

On 2014-11-20, dakupoto@gmail.com <dakupoto@gmail.com> wrote:
> Could some electronics guru pleas explain what 
> a "self-ballasted" LED lamp mean ? I have seen
> LED lamps, running off the AC line, and powered
> by a simple small 5V 1 Amp SMPS, but what exactly
> does a self-ballasted LED lamp mean ?

It depends on the context.


possibly it has a resistor inbuilt for operation at some specified
voltage.

-- 
umop apisdn

On 20/11/2014 03:40, dakupoto@gmail.com wrote:

> Could some electronics guru pleas explain what
> a "self-ballasted" LED lamp mean ? I have seen
> LED lamps, running off the AC line, and powered
> by a simple small 5V 1 Amp SMPS, but what exactly
> does a self-ballasted LED lamp mean ?

In series with something that approximates a constant current source for 
some reasonable range of applied input voltages. Could be as simple as a 
crude ballast resistor or a semiconductor based device.

A bare LED has a rather rapid increase in current through it once it 
starts to glow with a slightly higher applied voltage leading vastly 
increased current and then total destruction if you go too high.

You can do some cute physics experiements plotting V-I curves for LEDs.
eg.

http://www.phys.uconn.edu/~hamilton/phys258/N/led.pdf

Expect some LEDs to be destroyed in this practical.

-- 
Regards,
Martin Brown

Martin Brown wrote:

> A bare LED has a rather rapid increase in current

Like any other PN junction: I(U) is exponential.

	Best regards, Piotr

In article <227fa5bf-db57-412f-8fb7-a27513ada1c1@googlegroups.com>, 
dakupoto@gmail.com says...
> 
> Could some electronics guru pleas explain what 
> a "self-ballasted" LED lamp mean ? I have seen
> LED lamps, running off the AC line, and powered
> by a simple small 5V 1 Amp SMPS, but what exactly
> does a self-ballasted LED lamp mean ?

 it means it has the require components inside to 
accommodate a direct connection to a commonly known
source.

 Even with that, you still need to ensure you get the
correct one that matches the voltage you are attaching
it to.

Jamie

On Thursday, November 20, 2014 7:06:22 PM UTC-5, Maynard A. Philbrook Jr. wrote:
> In article <227fa5bf-db57-412f-8fb7-a27513ada1c1@googlegroups.com>, 
> dakupoto@gmail.com says...
> > 
> > Could some electronics guru pleas explain what 
> > a "self-ballasted" LED lamp mean ? I have seen
> > LED lamps, running off the AC line, and powered
> > by a simple small 5V 1 Amp SMPS, but what exactly
> > does a self-ballasted LED lamp mean ?
> 
>  it means it has the require components inside to 
> accommodate a direct connection to a commonly known
> source.
> 
>  Even with that, you still need to ensure you get the
> correct one that matches the voltage you are attaching
> it to.
> 
> Jamie

Thanks. Your explanation seems to be the most likely one.
We were looking at specifications for certification of
AC wall socket compatible LED lamp in as Asian country.

dakupoto@gmail.com wrote:
> Could some electronics guru pleas explain what
> a "self-ballasted" LED lamp mean ? I have seen
> LED lamps, running off the AC line, and powered
> by a simple small 5V 1 Amp SMPS, but what exactly
> does a self-ballasted LED lamp mean ?
   That term is also used for dual transistors; means "resistor(s) added".