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In order to cope with the increase in data traffic caused by the spread of smartphones, mobile phone carriers are increasing the number of base stations and strengthening their facilities.
Because mobile phones are an essential part of social infrastructure, base stations and other equipment must be reliable and operate reliably for long periods of time without breakdowns.
Company L, which develops, manufactures, and sells various power supplies such as switching power supplies, received a request from a communications equipment manufacturer to develop a power supply for the next model of a mobile phone base station. Director B of the company's design and development department looks back on the situation as follows:
"Base stations are installed not only on the rooftops of buildings and in residential areas, but also in remote mountain forests and remote islands without airports. If a part fails, it could cause major social problems, such as a cutoff in communications. For this reason, each and every part used in the equipment must be highly reliable. Power supplies are no exception."
Company L, which excels at customizing products to meet customer needs, was making steady progress in developing this power supply unit. However, they were facing issues with the cooling fan.
"When the lifespan of components used in base stations is short, frequent maintenance such as part replacement becomes necessary, which is very costly. Communications equipment manufacturers had a strong desire to reduce these costs. We have developed a wide variety of power supply units to meet customer needs. We were determined to develop a power supply that would meet those needs.
"We are good at circuit design thanks to the accumulated technology we have gained over the years. However, choosing a cooling fan, which has a major impact on the lifespan of the entire device, was a source of worry. We were looking for a long-life cooling fan that would make the device maintenance-free," said Mr. B.
The company had previously been using fans with an expected lifespan of 50,000 hours, but in reality they often needed to be replaced after around three years.
When Mr. B inquired to the manufacturer about why the expected life span in the specifications was only about half of what it actually was, he was told that the expected life span was defined at an ambient temperature of 25°C. The actual ambient temperature was about 50°C, which was thought to have shortened the life span unexpectedly.
For this reason, the power supply unit we developed required a highly reliable cooling fan that would continue to operate reliably for long periods without failure, even at high ambient temperatures.
*For more information on fan lifespan, see Knowledge Fan Basics: Fan Lifespan
First, Mr. B noticed that the "expected lifespan of 100,000 hours" was the expected lifespan when the ambient temperature was 60°C. When he consulted with a SANYO DENKI CO., LTD. representative about the durability of the fan, he was told that "if the ambient temperature rises by 15°C, the expected lifespan will be halved," and he decided to hear more details.
"With conventional fans, there was a significant gap between the expected lifespan and the actual lifespan, and we clearly saw that the reason for this was temperature conditions. If we are talking about the expected lifespan when the ambient temperature is 60°C, then we could expect to achieve high durability by using SANYO DENKI CO., LTD. fans. Furthermore, we learned that the lineup included products with an expected lifespan of 200,000 hours. 200,000 hours is a conservative estimate of about 20 years. We expected that this would exceed the equipment lifespan and contribute to reducing maintenance costs for communication equipment manufacturers." (Mr. B)
Mr. B immediately ordered an evaluation sample and conducted actual testing. The evaluation results showed that the cooling performance was equal to or better than the conventional product and there were no problems. He then visited Sanyo SANYO DENKI CO., LTD. 's Mt. Fuji factory to conduct a factory audit. The results left Mr. B very satisfied.
"I always thought that cooling fans and other parts were only randomly inspected, but SANYO DENKI CO., LTD. inspected all of them. They also had many other ideas for improving reliability." (Mr. B)
This thorough commitment to quality was the deciding factor, and the company soon decided to use SANYO DENKI CO., LTD. Denki's "Long Life Fan" in the power supplies for its new mobile phone base stations.
Mr. B had this to say about this hire:
"SANYO DENKI CO., LTD. 's Long Life Fan have enabled us to ensure high reliability, enabling maintenance-free operation over long periods of time, helping to significantly reduce maintenance costs for communications equipment manufacturers. We believe that the development of this highly reliable power supply unit will continue to contribute greatly to our company's growth."
For more information about Long Life Fan, please also see "Fan lifespan".
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