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palcal
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Joined: 12/10/2011
Location: AustraliaPosts: 1873 |
| Posted: 02:21am 11 Feb 2012 |
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Having a problem with the MM freezing when I turn off a fluoro on my work bench or unplug an inductive device. The spike on the mains must be causing the problem. I noticed in the original circuit diagram that there was a 330uf cap on the supply rail, which was not subsequently used. Thinking this may fix the problem I fitted one only to find the MM would not start up. Anyone have the answer.
Paul.
"It is better to be ignorant and ask a stupid question than to be plain Stupid and not ask at all" |
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BobD
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Joined: 07/12/2011
Location: AustraliaPosts: 935 |
| Posted: 07:34pm 11 Feb 2012 |
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Paul
What are you powering the MM with now?
Where did you put the 330uf capacitor, was it the 5 volt or 3.3 volt rail? |
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palcal
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Joined: 12/10/2011
Location: AustraliaPosts: 1873 |
| Posted: 09:18pm 11 Feb 2012 |
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Powering the MM with a plug pack (9 volt). I put the cap after the protection diode to ground, as in the original circuit in SC.
Paul.
"It is better to be ignorant and ask a stupid question than to be plain Stupid and not ask at all" |
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BobD
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Joined: 07/12/2011
Location: AustraliaPosts: 935 |
| Posted: 10:42pm 11 Feb 2012 |
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that's a 330Nf (NANO farad) cap not a 330Uf cap and it is probably not optional. I would expect it to be there to soak up power line glitches. |
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palcal
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Joined: 12/10/2011
Location: AustraliaPosts: 1873 |
| Posted: 12:58am 12 Feb 2012 |
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My mistake, but it does not come with the kit from Altronics. I will put a 330nf in and see how it goes.
Paul.
"It is better to be ignorant and ask a stupid question than to be plain Stupid and not ask at all" |
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BobD
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Joined: 07/12/2011
Location: AustraliaPosts: 935 |
| Posted: 01:08am 12 Feb 2012 |
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Paul
my kit was Altronics vintage december 2011 and the 330nf cap is labelled C13 and sits on the board next to the legs of the 7805. This cap was supplied with my kit. Anyhow, regardless of inclusion I am hopeful it will fix your problem. It shows in photos of the MM in the kit documentation and is labelled on the top with 334J100. Maybe it was an omission from your kit. |
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palcal
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Joined: 12/10/2011
Location: AustraliaPosts: 1873 |
| Posted: 01:12am 12 Feb 2012 |
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No that is in my kit although it is 100nf. The confusion arose because in the original circuit in SC the cap is marked 330uf, and I knew that was not in my kit.
Ran the MM overnight and it was frozen this morning am now running it via a 240v. mains suppressor to see what happens.
Paul
"It is better to be ignorant and ask a stupid question than to be plain Stupid and not ask at all" |
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palcal
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Joined: 12/10/2011
Location: AustraliaPosts: 1873 |
| Posted: 01:28am 12 Feb 2012 |
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Just checked again, I plugged my circuit board drill in and out a few times ,it caused the problem before, now it corrupted the LCD display but that righted itself on the next pass. Seems like the power supply could do with some more filtering. Although I must admit I have the devices plugged into the same power board, if I separated them it could be OK.
Paul.
"It is better to be ignorant and ask a stupid question than to be plain Stupid and not ask at all" |
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