36V 6A 120W Power Supply

This 36V 6A 120W Bench Power Supply is built around a XY-SK120X power management module obtained from Ali-Express for AU$23.19.

XY-SK120X

Here are the specifications (Note: they come in 60W and 120W variants)

Specification:

• Product Name: CNC DC buck boost power supply
• Product model: XY-SK60X/SK120X
• Input voltage: 6-36.00V
• Output voltage: 0.0-36.00V
• Output voltage accuracy: ± 0.5%+1 word (calibratable)
• Output current: SK60X: 0-5.000A; 120X：0-6.000A
• Output current accuracy: ± 0.5%+3 words (calibratable)
• Current resolution: 0.001A
• Output power: SK60X: 60W; SK120X: 120w
• Voltage resolution: 0.01V
• Data group storage: 10 groups
• Screen size: Over 1.8 inches, 38 * 29mm visible range
• Conversion efficiency: around 88%
• MPPT function: Supports MPPT solar charging
• Number of keys: 5
• Buzzer: Yes
• Soft Start: Yes
• Typical output ripple value: vpp-150mv
• Product size: SK60X: 86x50x45mm; SK120X：86x50x45mm. (Height does not include rotary encoder)

Protection mechanism

• Input anti reverse connection: Yes
• Output anti backflow: Yes
• Input undervoltage protection (LUP): adjustable 5.5-36V, factory default value 5.5V
• Output Overvoltage Protection (OUP): Adjustable from 0-38V, factory default value of 38V
• Output Overcurrent Protection (OCP):
• - SK60X: 0-5.2A adjustable, factory default value 5.2A
• - SK120X: 0-6.2A adjustable, factory default value 6.2A
• Output Overpower Protection (OPP):
• - SK60X: 0-80W adjustable, factory default value of 65W
• - SK120X: 0-150W adjustable, factory default value 125W
• Over temperature protection (OTP): adjustable from 0-110 ℃, factory default value of 95 ℃
• Overtime protection (OHP): 1 minute - 99 hours and 59 minutes, factory default disabled
• Overcapacity protection (OAH): 0-9999Ah, factory default disabled.
• Overenergy protection (OPH): 0-4200KWh, factory default disabled

Power supply module

The power supply module was also sourced from Ali-Express for AU$20.76.

Binding Terminals

I went for high quality binding terminals. They are a bit more expensive at AU$2.17 each also from Ali-Express.

Mains switch and socket

Power switch - AU$2.14 for 5 off at Ali-Express

Power socket - AU$2.09 at Ali-Express

3D printing

The STL files are attached. You can either take these to your 3D print shop or 3D print them yourself if you have access to a 3D printer. Layer height is 0.2mm and no supports are required. You will need to orientate the front, back and top to sit them flat on the build plate first.

Assembling

I recommend using connectors to wire up the component modules. The power supply module is held in place with 4 off 6mm M4 screws.

I also added a DC power socket as I have a number of pre-made cables that use a DC power plug. These are fine for low current projects where-as the binding posts are more suited to high current projects.

When connecting to the barrier terminal connectors on the XY-SK120X with high voltages or high currents, I strongly recommend using Ferrules when screwing in the cables. (See TO FERRULE OR NOT TO FERRULE).

Conclusion

The XY-SK120X power management module provides excellent features at a low cost. The final cost of this project was under AU$60.