Author Topic: Maynuo M8813 PSU testing - power on spikes  (Read 3700 times)

circuitous

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Maynuo M8813 PSU testing - power on spikes
« 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.

runem

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Re: Maynuo M8813 PSU testing - power on spikes
« Reply #1 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)?
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                   C
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                 SW

circuitous

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Re: Maynuo M8813 PSU testing - power on spikes
« Reply #2 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.

MJLorton

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Re: Maynuo M8813 PSU testing - power on spikes
« Reply #3 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.
Play, discover, learn and enjoy! (and don't be scared to make mistakes along the way!)