The Logisys PS350MA, targeted to small form factor (SFF) computers, measures only 4.9 x 2.5 x 3.9 inches (125 x 63.5 x 100 mm) (W x H x D). This unit raises several red flags as being a really bad product. First, it uses the SFX12V form factor, but the manufacturer is not aware of that, calling it a “Micro ATX” power supply. Second, it is sold as being a 350 W unit; however, the power supply label says that 350 W is the peak wattage, and the “average output” is 250 W. And, third, the label and product specification found online says the product only works at 220 V/50 Hz, but the unit clearly has a 110 V/220 V switch. Let’s see if our suspicions hold true or if this unit will surprise us.
This unit uses an 80 mm fan on its bottom part.
It doesn’t have an active PFC circuit and is based on the half-bridge topology, which is an obsolete design for PC power supplies, because it offers low efficiency.
The cables are permanently attached to the power supply, and they don’t have nylon sleeves. This power supply comes with the following cables:
- Main motherboard cable with a 20/24-pin connector, 13.4” (34 cm) long
- One cable with one ATX12V connector, 13.4” (34 cm) long
- One cable with one SATA power connector, 13.4” (34 cm) long
- One cable with two peripheral standard power connectors, 13” (33 cm) to the first connector, 5.9” (15 cm) between connectors
- One cable with two peripheral standard power connectors and one floppy disk drive power connector, 13” (33 cm) to the first connector, 5.9” (15 cm) between connectors
The cable configuration is really bad, with only one SATA power connector. Nowadays, even very low-end computers need at least two SATA power connectors, one for the hard drive and another for the optical drive.
All wires are thinner than the minimum recommended (20 AWG vs. 18 AWG).
Let’s now take an in-depth look inside this power supply.
- 1. Introduction
- 2. A Look Inside the Logisys PS350MA
- 3. Transient Filtering Stage
- 4. Primary Analysis
- 5. Secondary Analysis
- 6. Power Distribution
- 7. Load Tests
- 8. Main Specifications
- 9. Conclusions