MD input voltage

[ignotus]

Hi Dmitri,

I have a 10,000 mAh power bank on the way to try and see if by powering the module with this I can get rid of the self-triggering issue. I'm preparing the module to use this and I have a question: I'd like to have a switch to be able to toggle between the +5v source from the power bank (it's essentially just a battery) and the +5v source from the PC. The question is, can I just have a switch to toggle between the +5v sources, or do I also need to toggle the ground connection? i.e., if the +5v source is from the battery, does the ground connection also have to come just from the battery, isolated from the PC? I think there shouldn't be a problem but I'd just like to make sure.

[dmitri]

Ground of MegaDrum, PC and the MegaDrum power source (battery) must be common if you use USB. If you use standard MIDI ports then it doesn't matter - standard MIDI connections are optically isolated.

[ignotus]

Ok, thanks!

[dmitri]

Also look at https://www.google.co.uk/#q=optically+isolated+usb

[ignotus]

Also look at https://www.google.co.uk/#q=optically+isolated+usb

Thanks - interesting but it looks like a pricey solution. I don't gig/record or anything so I'm preferably looking for a cheap solution, if such a thing exists. I needed the UPS anyway for the PC, and I'll be using the power bank for my phone too, but if the latter still gives problems I think I have a usb-midi cable somewhere and I can try that: get power off the power bank and use the midi ports.

[ignotus]

Didn't get the power bank yet but I used an OTG cable to power the module off my phone - so far so good. Left the module on for a couple of hours and no trigger bursts. I'll leave it on all morning tomorrow and we'll see what happens.

[ignotus]

I received the power bank and have done some thorough testing, leaving the module on for several hours to see if the problem was still there: it seems to have been solved. The module draws so little current that it can also be easily powered with a mobile phone for several hours without much of an impact on battery charge. The 10,000 mAh power bank I bought will probably last for weeks (not continuously on of course) of daily use before needing a recharge.

[airflamesred]

Wow, reviving this thread an exact year later - what a coincidence.
Anyone having trouble with dirty elecrticity? I have a cable running from my mains consumer unit out to a shed where it transfoms into armoured cable and down to another shed. MD goes potty and is unusable. So, ATM I'm running an extention lead down to said shed and all is well.
Reading up on DE is a bit of a minefield (does it even exist?) I'd invest in one of these filters If I was sure it would work but thet are expensive and seem only to be a capacitor.
Any thoughts?

[airflamesred]

Bump

[ignotus]

I suppose the best course of action would be to buy a UPS, try it out, and if it doesn't solve the problem, return it. Mine significantly reduced the problem -I can go days without a single auto-triggering event- but it still occasionally happens, though when it does, with much less intensity and frequency.