Currently the circuit which is built already for LED (BXRA-56C5300) [datasheet attached] has 1 ohm current limiting resistance which will limit the current drawn by LED to 2.1 A when supply voltage is 24 V. The forward voltage of LED is 21.1 During normal operation max current flowing through it should be 2.1 A . Also the intensity is varied by using transistor in series with LED and resistor [Circuit Attached] . This setup is repeated for 32 such LED parallel connected to one DC 24 V supply .Such in total 64 LEDs are used powered with two different 24 V power supply.

Now the requirement now is to pulse the LED to its max rated current which is 4 A which can be achieved with supplying voltage around 28~29 V .Since this circuit is already built can't make any changes . So in order to achieve this voltage I was thinking of using SLA (car batteries) for this votlage .

I am thinking should I use battery to boost voltage which is supplied by 24V (AC TO DC) converter or use independently powering with SLA with voltage regulated to 28~29V . The requirement is to just pulse the LED with max current so it will glow at max intensity and then run again on regular 24 V supply. But this switching should be digitally controllable . Please let me know if I am missing out .

Thanks!

 

kindly consider GND terminal in schematic attached I forgot to add it

 

What wattage is the resistor? Which MOSFET? While the circuit is fine at the "simulation" level. The real world issue is heat, lots of heat. What are you doing about that?

 

What wattage is the resistor? Which MOSFET? While the circuit is fine at the "simulation" level. The real world issue is heat, lots of heat. What are you doing about that?

Wattage of resistor used is 4W and mosfet used is IRLZ34NPBF .All these LEDs are mounted on low thermal resistance heat sinks.Currently the setup is running and intensity control is achieved by sending PWM signal to gate of mosfet when supply votlage is 24V.

 

Do you want the same 1 ohm resistor in series with the LED when you apply the higher voltage?

 

Do you want the same 1 ohm resistor in series with the LED when you apply the higher voltage?

Yes! this circuit which is attached is already soldered and currently running with 24V DC supply. So I need to built a intermediate circuit which will be between SLA and LEDS. SLA should provide regulated 31 V and each LED string should drive 3.8~ 4 A which is max current for these LEDs.