The Illumination Systems of Microscopes 15 Years Ago
The light source illumination system is used to provide light for illuminating the specimen. There are two types of light sources used in microscopes: natural light and electric light. For microscopes that use natural light, their light source system only has one reflector. A reflector, also known as a mirror. It is installed on the mirror arm below the concentrator. A mirror has two reflective surfaces: one is flat and the other is concave. It can rotate freely in both horizontal and vertical directions. Its main function is to change the direction of indoor light (concave mirrors also have a certain condensing effect), so that the light is directed towards the condensing mirror.
Modern microscopes often use electric light sources for illumination. The light source system consists of a light source lamp circuit, a light source lamp, a lens, a reflector, a spotlight, etc. The entire light source lighting system is installed inside the lamp holder. Light source lamps generally use tungsten lamps or halogen lamps. The power of the lamp ranges from tens of watts to tens of watts. The voltage used for light source lamps is usually below 12V and requires adjustable voltage to change the brightness of the light. A brightness regulator is usually installed in the circuit of the light source lamp. By adjusting the brightness regulator, it is easy to change the brightness of the light projected onto the specimen.
There are various structural forms of the circuit for light source lamps. But usually, voltage regulation is carried out by changing the voltage of the primary coil of the transformer. The commonly used methods to change the voltage of the primary coil of a transformer include: changing the resistance division of the series connected primary of the transformer to change the primary voltage of the transformer; Using single junction transistors or bidirectional diodes to control the conduction angle of thyristors to change the primary voltage of transformers, etc.
