Characteristics of medical power supply and points for attention in use

Medical power supplies are generally applied to medical devices with isolation. It is a matter of life and health for both the patient being treated and the medical staff using the equipment. That's because, if a very small AC current is applied to the heart, it may cause myofibrillar abnormalities and neuromuscular damage to the heart. Therefore, medical devices require a stable voltage to power them, and medical power supplies are mainly used in consultation rooms, waiting rooms, massage rooms, and so on. So, here's what you need to know about medical power supply features and precautions for use.

　Medical power supplies are designed to be sensitive to medical sites and noise that require low-noise isolated power supplies.

　　Medical power supplies are characterized by

　　1. Noise such as the third harmonic can be removed by filtering the anti-interference function

　　2. Current waveform distortion caused by nonlinear loads can be isolated without polluting the grid. Prevents nonlinear load current distortion from affecting the normal operation of the AC power supply and polluting the power grid, and plays the role of purifying the power grid. Sampling at the input of the insulated transformer, so that the distortion of the nonlinear load current does not affect the accuracy of the sampling, to get a control signal that can respond to the actual situation.

　　3. A variety of installation methods easy to match with other equipment

　　4. Reliable application of artificial intelligence protection wall technology

　　5. Abundant interfaces and communication methods

　　6. Simple installation, space-saving

　　Precautions for the use of medical power supply

　　A customer once used a low-cost "medical power supply". The voltage of this power supply is 5V, the current is 200mA, the wholesale unit price is 5 dollars. Equipment using this power supply can be sold for tens of thousands of dollars. This amazingly low-priced power supply seemed to be very good, to the extent that it was so good as to be suspect, that is. Disassembly of this power supply unit reveals that there is only one single-sided printed circuit board, and to keep costs down, there are no metallized through-holes on the board. The circuit board is of surface mount construction with high component density. The component spacing is completely inconsistent with the creepage distance requirements and design standards set by the medical power supply and related safety regulatory agencies. Leakage currents are as high as 900mA, far exceeding the specification limits. The lead spacing of the power MOSFETs needs to become large to increase the leakage distance, but the power supply did not handle it this way, probably because of the manufacturing cost and the more space it takes up. The aluminum heatsink is inserted into the board with a couple of claws and secured with solder. If not handled correctly, the heatsink tends to come loose. This power supply unit meets just the right amount of commercial EMI-RFI requirements, but does not meet the requirements for medical power supplies.

　　There are several other problems with this power supply, such as virtual soldering everywhere within the power supply. When in use, failures can occur at any time, even when assembled correctly. The power supply is sold as a medical power supply, but is not itself designed to meet medical requirements and has no relevant documentation or technical specifications other than input voltage, output voltage and current. Therefore, when purchasing a medical power supply, it is important to consider the risks associated with it, and to purchase from a manufacturer that is creditworthy, provides documentation of compliance with the relevant standard criteria, and is able to comply with quality and reliability standards and requirements.

　　The above introduction is the medical power supply characteristics and precautions for use. For more information, feel free to contact us! Our company has many years of experience and is always looking forward to your joining us.