Schematic diagram of battery-powered synchronous flash light circuit

When photography enthusiasts create still life or portrait photography indoors, the arrangement of photographic lighting is an important link. In addition to high-power photographic lights, using synchronized flash lights as shown in the figure is a low-investment, energy-saving option.

Component selection: VT1 should be a power tube with a current of more than 0.5A, a withstand voltage of more than 30V, and an amplification factor of more than 200. The photosensitive triode can be replaced by the infrared receiving tube in the infrared remote control device. Since the xenon lamp flash has strong near-infrared radiation, the infrared receiving tube can avoid the interference of ambient stray light. The unidirectional thyristor can be selected from the common 1A and withstand voltage of more than 400V. The high-voltage rectifier tube VD1 works in a high-frequency oscillation state. It is not suitable to use a common rectifier tube, such as 1N4007. It is advisable to use a fast recovery diode for switching power supply with a withstand voltage of more than 1000V. C3 in the trigger circuit cannot use ordinary capacitors because the voltage in standby mode exceeds 300V. A CBB capacitor with a withstand voltage of 400V should be used. The flash tube of the built-in flash of the camera is 20mm to 30mm long. The size of the main energy storage capacitor is related to the flash tube and the flash index. It can be selected according to needs and possibilities. The operating frequency of the oscillation transformer is about 10kHz, the core is E-type ferrite, and the reference turns of L1, L2 and L3 are 12, 24, and 1250. The reference turns of L1 and L2 of the trigger coil are 20 and 600, and the secondary coil L2 should be wound in 3 sections.