This is a very simple LED Strobe light with well-known timer 555. P1 is used to set the frequency. R1 determines the length of bursts. R2 determines the maximum frequency that can be set using P1. R3 determines the current to the LEDs. As a power switch, I used IRL3103S SMD MOSFET (30V, 64A, 12mR), but you can use almost any low-voltage MOSFET (eg, IRFZ44, IRFZ42, IRFR024N, CEM9926, FDN5630, IRLL014N, 06N03LA, MTB1306, 2SK3296 ...). Circuit can be adjusted for different types, colors and quantities of LED, just change the value of R3. I used 36 white LED 5mm diameter, max continuous current of 30mA (involved in 3 x 12). The sum of LEDs' voltage drops, connected in series, must always be less than the supply voltage.