Types and Selection of DC Stabilized Power Supplies
DC stabilized power supplies can be classified into chemical power supplies, linear stabilized power supplies, and switch type stabilized power supplies according to habits. They each have various types: chemical power supplies. Dry batteries, lead-acid batteries, nickel cadmium, nickel hydrogen, and lithium-ion batteries that we usually use belong to this category, each with its own advantages and disadvantages. With the development of science and technology, intelligent batteries have emerged; In terms of rechargeable battery materials, American researchers have discovered an iodide of manganese, which can be used to produce environmentally friendly rechargeable batteries that are inexpensive, compact, have long discharge times, and maintain good performance even after multiple charges. A common feature of linear stable power supplies is that their power devices operate in the linear region, relying on the voltage drop between the adjustment tubes to stabilize the output. Due to the large static loss of the adjustment tube, a large radiator needs to be installed to dissipate heat. Moreover, due to the transformer operating at the power frequency (50Hz), it is relatively heavy. The advantages of this type of power supply are high stability, small ripple, high reliability, easy to make into multiple channels, and continuously adjustable output products. The disadvantages are large size, heavy weight, and relatively low efficiency. There are many types of stable power supplies, which can be divided into regulated power supplies, regulated current power supplies, and regulated current (bistable) power supplies that integrate regulation and current regulation. From the output value, it can be divided into several types: fixed-point output power supply, band switch adjustment, and potentiometer continuous adjustable. From the output indication, it can be divided into pointer indication type and digital display type, etc. A type of stabilized power supply that is different from linear stabilized power supply is switch type stabilized power supply. Its circuit types mainly include single ended flyback, single ended forward, half bridge, push-pull, and full bridge. The fundamental difference between it and a linear power supply is that its transformer does not operate at the power frequency, but rather operates at several tens of kilohertz to several megahertz. The function tube does not work in the saturation and cutoff zone or switch state; Switching power supply is named after this. The advantages of switch mode power supply are small size, light weight, stability and reliability; The disadvantage is that compared to linear power supplies, the ripple is relatively large (generally ≤ 1% VO (P-P), and good ones can achieve tens of mV (P-P) or less). Its power can range from a few watts to several kilowatts. The price range is from 3 yuan to over 100000 yuan per watt.
