# Basic custom power supply?

#### k1ng 1337

Joined Sep 11, 2020
85
Hi I have several circuits that I would like to permanently mount. There are many power supply options on the market but I'm looking to build some myself that are matched to the application or find the best units in terms of efficiency and low purchase cost. For example I have an Arduino clock which requires 5v and peaks at 100ma, this circuit would be exclusive to the power supply so filtering and other features may prove redundant. All my circuits are 5v DC and no more than 1A. All comments and opinions are appreciated.

#### KeithWalker

Joined Jul 10, 2017
1,789

#### k1ng 1337

Joined Sep 11, 2020
85
I use these in most of my small projects. They are available in 3.3V, 5V and 12V output versions, input voltage is 90 ~ 264VAC. They work very well and you can't beat the price - that's \$Canadian!

View attachment 238526
That is indeed a hard price to beat.. I was thinkin of using generic 5v cell phone chargers but the datasheets are not available unless buying from a dealer such as Apple and at their elite prices.

HLK-PM01 specs

• Input Voltage: 100-240V AC
• Input Frequency: 50-60Hz
• Output Voltage: 5V
• Output current: 600mA
• Power: 3W
• Output peak current: 1000mA
• Maximum Input current: 0.2A
• Efficiency: 70%
• In-built short circuit and over current protection

What is maximum input current? Also the efficiency is 70.. is this normal for ac-dc conversion? Or do the In-built short circuit and over current protection come at the cost of efficiency? Both of these features are somewhat redundant in my designs but still nice to have considering the losses in any of my designs amount to pennies on the power bill.