This strobe gives a visual indication of a sensor input. The input signal causes Ul, a light dependent resistor, to chaijge CI
and C3 through R4. When NE1 fires, C3 discharges into SCR1, which triggers it and causes C2 to discharge through trigger transformer Tl, which triggers Flashlamp FL1, The 330-V supply should have about 50 to 100 /iF output capacitance. Ll supplies about 25-mH inductance to prolong the flash and the life of FL1.