Power supply problems solved January 03, 2014 08:55AM |
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Re: Power supply problems solved January 03, 2014 09:27AM |
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Re: Power supply problems solved January 03, 2014 12:23PM |
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Re: Power supply problems solved January 03, 2014 01:04PM |
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Re: Power supply problems solved January 03, 2014 01:30PM |
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Re: Power supply problems solved January 03, 2014 01:37PM |
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Re: Power supply problems solved January 03, 2014 01:44PM |
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Re: Power supply problems solved January 03, 2014 02:07PM |
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Quote
DennisCowdery
d) wire a 1A 30v (piv) schottkey diode across the heater bed -observe direction!!
Re: Power supply problems solved January 03, 2014 04:06PM |
Registered: 10 years ago Posts: 314 |
The power board does have 22R and 30R resistors on the lower side (probably obscured by the wiring loom). I presume these are the loads for the other supplies.Quote
chriscain
I saw this post on a blog about a Mendal 90
[hydraraptor.blogspot.co.uk]
The interesting bit for PSU info is that the PSU used in this kit looks the same as the Ormerod one
and it says
"I also changed the PSU to an ATX500 because I can buy them in the UK with CE approval and they come with integral mains inlet and switch, obviating the need for the kit builder to do their own mains wiring. It is also shorter, allowing room for the Melzi (which is very long and thin). The downside is it needs a pair of load resistors on the 5V and 3.3V to get the 12V rail to be close to 12V under load. These are provided in the kit."
I have noticed that the 12 volts drops to about 11.5 when the bed is on
I wonder if drawing something from the 5/3.3 rails would improve this regulation.
Chris
Re: Power supply problems solved January 03, 2014 04:51PM |
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Re: Power supply problems solved January 03, 2014 06:01PM |
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Re: Power supply problems solved January 04, 2014 10:50AM |
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Re: Power supply problems solved January 04, 2014 10:55AM |
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Re: Power supply problems solved January 04, 2014 10:57AM |
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Re: Power supply problems solved January 04, 2014 10:59AM |
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Re: Power supply problems solved January 04, 2014 11:04AM |
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Quote
DennisCowdery
I have seen values of 1uF mentioned. If people are putting this across their FET then they will put a big transient load on the FET on turn on (I have popped them in the past this way), they will also inject current into the PCB
Re: Power supply problems solved January 04, 2014 01:11PM |
Registered: 10 years ago Posts: 300 |