I have a 30 Watt LED in the original fitting which looks like one giant heat sink. The LED is still ok but the driver was hit by lightning.

I want to use the LED and housing But have only one. On the housing it says 24 Volt DC supply.

If I get the driver wrong I will blow the LED and I have no chance at trying again.

I have attached a driver I think "may work"

Thanks

Rodney

 

Hello,

You have connedted the LM317 in the wrong way.
Now you have a 1.25 Volts voltage regulator with a resistor in series to the load.

Here is how it should be connected according the datasheet:

It will be very inefficient, as all current X the voltage drop will be dissipated by the LM317.

Bertus

 

Hello,

You have connedted the LM317 in the wrong way.
Now you have a 1.25 Volts voltage regulator with a resistor in series to the load.

Here is how it should be connected according the datasheet:

It will be very inefficient, as all current X the voltage drop will be dissipated by the LM317.

Bertus

Thanks very much for the help. I really don't have any idea how else to do it. The whole fitting is aluminium and I hope that will be enough.

Thanks again

Rodney

 

Hello,

Keep in mind that the LM317 will drop about 2 Volts and the resistor an other 1.25 Volts.
You will need a headroom of about 4 volts for the correct current delivered to the led.

Bertus

 

Hello,

Keep in mind that the LM317 will drop about 2 Volts and the resistor an other 1.25 Volts.
You will need a headroom of about 4 volts for the correct current delivered to the led.

Bertus

So I should use the supply voltage of 20 Volts in my calculations to compensate for this

 

Hello,

If the led needs 24 Volts to work fully, the powersource should be about 28 Volts.

Bertus

 

ok Thank you