Constant voltage costant current for cob led

[Jamshi]

The voltage from a car battery can be anything from 11V to 15V.

If you use just a resistor, you must be sure the current through the LEDs will never be too high at the maximum voltage.

However, with a 9V LED assembly, that means the resistor may be dropping anything between 6V and 2V; the current will vary by a factor of three times over the battery voltage range, from maximum at 15V down to one third at 11V.

The three ohm resistor would give around 2A at 15V (engine running and battery at full charge) down to ~0.67A with the battery near flat.

That's why an electronic regulator is better, if you want constant brightness.

Can you suggest me an electronic regulator which is suitable for my project

 

[Pommie]

That's why I suggested "starting" with a resistor to see how hot it runs and what voltage appears across it.

Mike.

 

[Jamshi]

Okay

 

[ronsimpson]

Can you suggest me an electronic regulator which is suitable for my project

See post #6 & #14.

 

[Jamshi]

See post #6 & #14.

Can you help me to get there..
Where to find post 6 and 14..?
Topic name please...

 

[rjenkinsgb]

Can you help me to get there..
Where to find post 6 and 14..?
Topic name please...

This topic - look at the post numbers at the right of the header on each post; eg. yours above was post #25
6 & 14 will be on page one.

 

[Jamshi]

Ok

 

[ronsimpson]

Evaluation board from TI. 1.5A buck current source

 

[Jamshi]

Anyone knows an alternate for LEDA(qx9920).. Because it is used in the circuit, unfortunately it burned.. Now i made this post to rebuild the circuit... This circuit is a c6 h4 led..

 

[Jamshi]

My project is to rebuild this burned circuit...
The details of the cob provided here

 

[Jamshi]

Hello, anyone there...