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Power Supply Issue

Posted: Jan 27th, '16, 12:06
by jeremy
Hi,

I've finished building the power supply. Two issues:

1. Positive 15 voltage pad shows 13.36V, this is obviously not within 5% tolerance, is this ok or not?
2. Negative 15 voltage pad shows nothing (0V) when tested.

The positive 5V pad shows a perfect 5V. My multimeter works fine.

All components checked over for bridges, polarity, obvious defects etc. All OK.

Edit:

Also, when I bridge connections on C5, there is a spark however bridging C7 produces noting.
Any help much appreciated!

Thanks a lot,

Jeremy.

Re: Power Supply Issue

Posted: Jan 27th, '16, 12:31
by ElSchtroumpf
Go over the earlier posts on the forum, I remember a few threads where this problem was discussed.

Re: Power Supply Issue

Posted: Jan 27th, '16, 13:02
by ikke
I think you are using a DC PSU and that's why the negative rail doesn't check out. You need an AC PSU to power the Yocto.

The +15 Volt rail needs a little load to check out correctly. Try to measure with a resistor (4,7K) between the output of +15Volt and Ground.

Re: Power Supply Issue

Posted: Jan 27th, '16, 18:38
by ikke
I made a mistake concerning the resistor as a load... That applies to -15V rail.
Just start with the correct PSU and let's see what readings you get than.

viewtopic.php?f=16&t=373

Re: Power Supply Issue

Posted: Jan 27th, '16, 21:56
by jeremy
Ugh, what a nightmare!

No probs, my bad. Would this be suitable: http://uk.farnell.com/ideal-power/77db- ... dp/2368009?

It's only rated at .67A, would this be suitable?

Thanks,

Re: Power Supply Issue

Posted: Jan 28th, '16, 08:11
by another_universe
I think it' too weak , has to be 1A or more.

Re: Power Supply Issue

Posted: Jan 28th, '16, 10:38
by shinotoko
Hey Jeremy,

I've just ordered this one https://www.esr.co.uk/electronics/power ... plugac.htm, its 16V AC 1.6A, i got the link on this forum from people that have said its works perfectly!

Shinotoko

Re: Power Supply Issue

Posted: Jan 28th, '16, 17:54
by jeremy
shinotoko wrote:Hey Jeremy,

I've just ordered this one https://www.esr.co.uk/electronics/power ... plugac.htm, its 16V AC 1.6A, i got the link on this forum from people that have said its works perfectly!

Shinotoko
Hey,

Thanks for pointing that one out! The only thing I noticed about that is that it states it uses a 2.5mm barrel plug. The socket sold by Mouser in the pre made BOM is a 2.1mm socket and thus the power supply wont fit straight out the box. Obviously you could buy a 2.5mm socket, alternatively, chop the 2.5mm off and replace with a 2.1mm. :)

Take care,

Jeremy