A friend of mine uses a SONY VIAO 505 laptop, which is very small and exquisite. However, the original power supply is quite bulky, making it inconvenient to carry back and forth to work every day. Therefore, he wanted to get a smaller power supply, keeping one set at home and another in the office, and taking the smaller one when traveling on business. But Sony's original equipment is hard to find and very expensive. So, I used my existing HP and FUJISTU power supplies to DIY one for him, which turned out to be very compact and practical. Below, I will introduce the making process to everyone.