You don't really realize how useful a electronic load is at the bench until you get one. Lots of troubleshooting done with the smaller 150W BK unit I have...sometimes I wish I had a bigger one but that's for another day! Thanks for sharing Kerry!
Thank you for the video. I have the TekPower 3710A and I also got mine off of ebay. It was brand new in a sealed box from a company going out of business and for well under $200.00. it has been working fine and seems to be well designed and built. I really appreciate that your link allowed me to download the schematics. Thanks again for posting.
Enjoyed the teardown Kerry - your homemade DC load is what brought me to your channel. I own one of the cheaper imports from Ebay as well as a Secnore PSL60, both work well for what they are.
My 3711A is about 8 years old and has developed a strange problem. The two voltages shown on the display are about 1/10 of the actual voltage. Originally, the error was time dependent (accurate when first turned on then after awhile would change to the 1/10 of actual value). Now it is permanently about 1/10 of actual voltage. The load settings (A, W, R) have tested accurate with external test equipment. It appears to be a problem with how the unit is sampling/conditioning/scaling the measured voltages. I've just pulled the schematic from your webpage so I will study. Any tips?
@@KerryWongBlog That's really good then considering the units price. According to chat on the EEVblog, the Maynuo units have a common ground with the input and the comms, so you have to be careful plugging it into your pc and DUT!
A warning for anyone using this device. The ground of the serial port is connected to the negative post of the input. If certain electrical connections fail, large currents can pass through your data cables and PC.
So the input voltage and current have the same specs but one only handles half the wattage? Sounds like a software control difference. Attention hackers....
I will give it a test to see what the voltage drop along the terminal is at the maximum rated load. But given how large the connectors are and the way they are mounted I don't think the voltage drop would be significant. But I will test it out, stay tuned.
If you look at Mininmum resolution you will see they are using 12bit ADC, not 10bit. You were looking at accuracy. Different thing, and looser than resolution. Obviously. It is mostly due to calibration, drift, noise, and components used, etc.
You don't really realize how useful a electronic load is at the bench until you get one. Lots of troubleshooting done with the smaller 150W BK unit I have...sometimes I wish I had a bigger one but that's for another day! Thanks for sharing Kerry!
Yeah, I agree, electronic load is very useful. I built the 1kW one so that I could test my battery banks and some beefy power supplies...
Thank you for the video. I have the TekPower 3710A and I also got mine off of ebay. It was brand new in a sealed box from a company going out of business and for well under $200.00. it has been working fine and seems to be well designed and built. I really appreciate that your link allowed me to download the schematics. Thanks again for posting.
Enjoyed the teardown Kerry - your homemade DC load is what brought me to your channel. I own one of the cheaper imports from Ebay as well as a Secnore PSL60, both work well for what they are.
Thanks! For hobby uses, those eBay ones would be fine. The PSL60 is a very nice one.
My 3711A is about 8 years old and has developed a strange problem. The two voltages shown on the display are about 1/10 of the actual voltage. Originally, the error was time dependent (accurate when first turned on then after awhile would change to the 1/10 of actual value). Now it is permanently about 1/10 of actual voltage. The load settings (A, W, R) have tested accurate with external test equipment. It appears to be a problem with how the unit is sampling/conditioning/scaling the measured voltages. I've just pulled the schematic from your webpage so I will study. Any tips?
Really interesting video. Can you comment on the isolation, i.e. are the inputs separated from ground?
Hi Marcus, yes the inputs are isolated from ground.
@@KerryWongBlog That's really good then considering the units price. According to chat on the EEVblog, the Maynuo units have a common ground with the input and the comms, so you have to be careful plugging it into your pc and DUT!
Seen a Teardown of the 3710A looks identical. Wonder if its just firmware like most these low cost items.
A warning for anyone using this device. The ground of the serial port is connected to the negative post of the input. If certain electrical connections fail, large currents can pass through your data cables and PC.
Thank you for sharing this video
So the input voltage and current have the same specs but one only handles half the wattage? Sounds like a software control difference. Attention hackers....
it should have a sensing port. there will be a significant power loss under 30amps load...
I will give it a test to see what the voltage drop along the terminal is at the maximum rated load. But given how large the connectors are and the way they are mounted I don't think the voltage drop would be significant. But I will test it out, stay tuned.
IRF3205's ???, how do they do 360V ?
I've been wondering the same thing, Perhaps it's something to trip-up clone producers?
If you look at Mininmum resolution you will see they are using 12bit ADC, not 10bit. You were looking at accuracy. Different thing, and looser than resolution. Obviously. It is mostly due to calibration, drift, noise, and components used, etc.
Why I can't manage your voice? I tried but no way.
Hope you find the video informative and useful, that is something I do have control over :-)
@@KerryWongBlog yes, your videos are informative and fun, your voice it's only a problem of mine and I can't explain why.
www.eevblog.com/forum/other-blog-specific/teardown-of-an-array-3711a-300w-dc-electronic-load/