LED board with constant + strobe operation circuit design
A traditional strobe light works by dumping the energy stored in a capacitor to the light element at high voltage for short duration (a few hundred us).

A LED cannot work this way. Typically, you can over-drive a LED to no more than 2 times the maximum rated current for short duration at low duty cycle (for example, 500 us at 1% duty cycle).

Here are the suggestions. Organize the 16 LEDs into 4 strings. Each strings would take up to 3.2V x 4 = 13V at maximum rated current of 0.25A. This can be driven comfortably with very cheap and common LED driver from 24V.

You can try to drive all 4 strings in parallel with one driver. In this case, you may want to hand match the forward voltages of the 4 strings. I think using 4 drivers for the 4 strings could be a better choice.

Pick a driver that has a current setting input. Set the current to 0.05A for dim mode. For the strobe mode, pulse the driver's enable input for the duration desired and at the same time force the current setting to full power. Full power could be 0.25A or you can consider over-driving of up to 0.5A for a short duration strobe.



In response to the comments: a current limit plus a large input capacitor can allow the LED circuit to operate at higher power in short duration than the power supply can provide.

There is a common current limit circuit based on the LM317. One disadvantage of the LM317 circuit is the waste of around 3 to 4V.

Another simple alternative is as followed. The waste can be as low as 0.7V near current limit. Size R2 to the Vbe of Q1 for the current limit. The precision is based on the Vbe so you do need some head room between the current needed and the current available for setting the limit in between.







simulate this circuit &ndash; Schematic created using CircuitLab

Above circuit edited to add R3 if needed. R3 is for reducing Vgs which is very likely needed for 24V operation.