| 摘要 |
A storage capacitor 4 is charged from the mains supply into a transformer 1, or voltage multiplier and a rectifier 2, a flash capacitor 7 is connected to the capacitor 4 via a emitting resistor 5 and a GTO thyristor 6, and the capacitor 7 is connected via an SRC (Symmetrically blocking) thyristor 8 to a flash tube 9 which is fired by a Testa transformer 10. The arrangement eliminates the dependence of the flash frequency and the flash energy on the de-ionising time of the gas discharge flash tubes employed. Control circuit 11 turns off the GTO thrysistor 6 when the flash capacitor 7 is fully charged. Resistor 5 is chosen so that the GTO thyristor 6 has a substantially smaller loading than the thyristor 8. At higher flash frequency and with ionised flash tubes, discharge of the flash capacitor 7 through the flash tube 9 may be controlled solely by the thyristor 8. The arrangement may be used for observations in flow technology, such as bubble formation in cloudy liquids. Flash frequencies of 5 KHz to 10 KHz may be achieved. <IMAGE> |
