Introduction
I built my first power supply with a soldering iron when I was 14 years old. It was a simple design with about 10 components including a massive transformer, bridge rectifier, capacitors, resistors, a darlington transistor, and a zener diode. This is what is known as a linear power supply and if you want to learn more about how to build one, I found a good design guide. Although this approach worked for powering an audio amplifier for my electric violin, it was large, heavy, and inefficient creating about a watt of heat for every watt of usable power.
30 years ago, more efficient switched-mode power supplies were rarely used outside computers and specialized equipment as the components were expensive and efficiency was a lesser concern. Now, switching power supplies are found in tiny 10 watt cellphone chargers as well as multi-kilowatt units powering racks of data center servers. The key reason for this change is that switched-mode power supplies are typically 80-95% efficient compared to 50-60% in the best linear power supplies. They also take up far less space than linear power supplies. The only drawback is added complexity with dozens of components compared to the ~10 components in my DIY power supply build.
Over the last few years, I’ve collected several USB-C power supplies of various capacity and quality levels (all are switched mode). But until now, I never really thought about them that much. Today I have the pleasure of showing off the EBL TC-073CA65 and I’ll dive deep into its performance.
Full disclosure: While this is not a sponsored post, the product showcased was provided at no cost for evaluation purposes. Products received in this capacity are destined for teardowns, future device interoperability testing, and/or charitable donations.
Feature Summary
- Universal 100-240V input
- 1 meter AC/Mains cable (permanently attached)
- 2 USB-C outputs (5V, 9V, 12V, 15V, 20V up to 3.25 amps)
- 1 standard USB-A output (5V 1 amp)
- 1 quick-charge USB-A output (5V, 9V, 12V, 20V up to 30 watts)
- 2 AC/Mains receptacles (1625W max combined rating)
- Quick charge protocols: QC4+, PD 3.0, QC3.0, QC2.0, SCP, FCP, AFC, PE+
Unboxing & Physical characteristics
Within an outer printed carboard shell was a plain white carboard box containing a user manual and the PSU wrapped in a thin white plastic bag. The PSU has a textured plastic finish that is easy to grip with orange printing on the side. Three of the ports have orange accents inside with the fourth being black. The AC/Mains cord is about 1 meter long and terminates with a 3-prong NEMA 5-15P (USA-style) connector.
Testing
I received the power supply right before going on a train ride on the Amtrak cascades and figured a good way to force myself to use it would be to leave my regular phone and laptop chargers at home and just go with this one. It did not disappoint and charged my laptop and phone throughout the ride and short stay out of town.
Voltage
Back home, I did a little more in-depth testing with some USB power meters. Rather than type a whole essay and take meticulous photos, I made a video.
Of note:
- 20V mode output was ~19.2V at 65W+ output power level which does meet USB-IF specifications, but just barely. It exceed its claimed current rating of 3.25 amps and actually delivered more than 70 watts. 5V, 9V, 12V, 15V were all perfectly on spec with respect to voltage and amperage.
- Both of the USB A ports were able to do 5V @ 3 amps while the spec said only 5W would be delivered from one of the ports. This was a nice surprise.
- Overdriving a USB-C port beyond ~80W or so resulted in the voltage immediately dropping down from 20V to 15V which is an interesting way to handle over power protection (OPP). With other power supplies, what typically happens is an immediate port reset with power delivery negotiation starting from scratch at 5 volts. I’m not sure whether jumping directly to 15V is a good thing or a bad thing, but it served its purpose of not overheating the PSU or causing any damage to the charging device. Restoring the load to something normal resumed the 20V charging.
- Overdriving a USB-A port beyond 5V @ 3A (without a quick-charge mode enabled) resulted in immediate port shutdown which is good. Restoring a normal load resumed charging immediately.
Heat
After charging at ~65W for over an hour, the PSU reached about 30°C above ambient. In my case with an unheated workspace, this was a rise from ~13°C -> 43°C. In more typical indoor environments, I expect the temperature to be closer to 50-60°C which is a little warmer than I’d like, but on-spec for electronic components which won’t be directly handled for longer than a few seconds at a time. I did not notice any smell emanating from the PSU which is good.
Efficiency
When idling, the power supply consumed about 0.3 watts which is typical. So, like the Sindox 100W PSU I tested last year, it is best to unplug it when not in use. I’ve summarized my efficiency results below. which you can see in the YouTube video as well: https://www.youtube.com/watch?v=pfnzjFVvF7M&t=507s
Voltage quality (noise/ripple)
Most modern power supplies have some amount of voltage ripple or minor fluctuations up and down from the desired voltage. Better power supplies tend to use more complex designs and higher quality components which help to reduce this ripple so that devices can have the smoothest power possible. Unfortunately, the USB-IF specification doesn’t provide guidance on voltage ripple for USB-C power supplies. For computer power supplies, the ATX specification allows 120mV ripple on 12 volt rails and 50 mV on 5 volt rails or about 1% ripple. The 300 watt, 24-volt power supply on one of my 3D-printershas about 150mV or 0.6% ripple. So we’ll use those for comparison.
I found that the EBL PSU has a switching circuit that runs at ~300KHz and has fairly low ripple (40-70mV) from 5V to 15V up to 45W (0.5%-0.8% ripple), but has more ripple on the order of 150-200mV at 19V (0.8-1%) with higher power levels. I can’t really say whether this result is good or bad but is comparable to mid-tier ATX power supplies. I’ll have to test more USB-C power supplies to know for sure. Video evidence with my oscilloscope is here: https://www.youtube.com/watch?v=pfnzjFVvF7M&t=507s
Conclusion
The $30 EBL TC-073CA65 is compact, relatively lightweight, and fulfills the advertised claims more or less. It appears to be a re-brand of the Baseus CCDK65S which is $10 more expensive, but comes with a USB-C cable in the box. Performance is similar to what AllThingsOnePlace found for the Baseus model so this isn’t a high performance power supply, but does have an interesting feature set.
There are a few variants of these PSUs. The $60 100W TC-073CA100 actually performs much better with active power-factor-correction. It is equivalent to the Baseus CCDK100US which AllThingsOnePlace tested as well. There is also a $40 model that has a built-in HDMI/data hub.
Both the EDL and Baseus models lack USB-IF certification, but USB-IF doesn’t have a robust validation program for multi-port PSUs so I really can’t fault the manufacturers. The voltage in 20V mode is a little low at ~19.2V which just barely meets the USB-IF specification. The idle power consumption isn’t great, but not terrible either. I think it would be terrific to add a physical switch given that the unit acts as a power bar as well. Speaking of the power bar feature, I mentioned in the video that I couldn’t imagine myself using it, but I was wrong. The two AC/Mains receptacles do come in handy. I have not tested them with a hair dryer to see about the 1625W claim – but I will add notes here if I see anything amiss. I was a little disappointed to see a lack of UL or Intertek certifications on the EDL model – but the equivalent Baseus model does have an Intertek rating so it probably meets the same spec.
Overall, The EBL TC-073CA65 is fine, but the 100W model TC-073CA100 is a higher-tier PSU and is the one I would recommend even if you don’t need 100W.
Dan S. Charlton 
