MJLorton Solar Power and Electronic Measurement Equipment Forum

Product Reviews => Product Reviews => Topic started by: circuitous on January 27, 2014, 09:26:48 AM

Title: Maynuo M8813 PSU testing - power on spikes
Post by: circuitous on January 27, 2014, 09:26:48 AM
After having a microcontroller get damaged on a breadboard, I stopped using my Maynuo M8813 power supply until I could get around to testing it.

Here's a video showing some nice capabilities of the power supply, along with some disappointments.
https://www.youtube.com/watch?v=rvuiWfLU18E

This video just tests a few aspects of the PSU that Martin didn't cover in his big review of the M8800 series. https://www.youtube.com/watch?v=gqGjNlpTQlk

Spoiler Alert:  If you have one of these power supplies, follow the often given advice to disconnect your DUT before switching the PSU on or off (at the hard switch).

I felt this video got a bit long, so I trimmed it as much as I could... I'll have to work on my speed!  I was also recovering from a cold, so the audio changes a bit from clip to clip.
Title: Re: Maynuo M8813 PSU testing - power on spikes
Post by: runem on February 12, 2014, 06:44:34 PM
I'm taking a wild guess here, but could this problem be caused by a mains switch that's not bypassed properly and then makes the electronics in the Maynuo go nuts on you?
What happens if you solder in a capacitor over the switch contacts (on both line and neutral if DP switch)?
Code: [Select]
                   C
          ------||--------
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                 SW
Title: Re: Maynuo M8813 PSU testing - power on spikes
Post by: circuitous on February 12, 2014, 08:18:51 PM
Interesting, thank you for the suggestion, I'll have to open it up and see what might be going on.  I have other power supplies that don't have this problem, and I have been using those.  I will probably open up the Maynuo pretty soon.

I put a reverse zener 5V5 diode across the power connection into the breadboard and that has suppressed the spike to 5V, which should be good enough if I forget to disconnect the board before hitting the PSU switch.
Title: Re: Maynuo M8813 PSU testing - power on spikes
Post by: MJLorton on March 07, 2014, 12:51:31 PM
Sorry, I missed the first post...I think I have another problem with the supply too. I need to check for the power on issue as well.

Once I've confirmed I'll add feedback here.

Cheers,
Martin.