This is example of a simple inverter that can be used to power fluorescent lamp and a small strobe. This circuit will produce over 400VDC from a 12 VDC, 2.5 A power supply or marine battery or an auto. This circuit is very simple because it does not require custom transformers or coils. Also all components are readily available. Here is the circuit :
The output of this circuit depends on the input voltage. If we use the component values given, we will get offer 400 V from 12 V supply and charge a 200 uF capacitor to 300 V in under 5 seconds. We must use a good heat sink because Q1 does get quite hot. D1 is used to prevents significant reverse voltage on the B-E junction and provides a return path for the base drive. R2 is used to limits surge current through D2.
WARNING: Output is high voltage and dangerous even without large energy storage capacitor. With one, it can be lethal.