Author Topic: machine 'seized' during burn  (Read 305 times)

Zax

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Re: machine 'seized' during burn
« Reply #15 on: August 16, 2019, 04:26:00 AM »
Yes, the pull down resistor must have disconnected. It's unlikely it would fail.

ggallant571

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Re: machine 'seized' during burn
« Reply #16 on: August 16, 2019, 07:04:05 AM »
I think 4.5A at 12V is marginal for a 2.5A fixture. Chinese 4.5A is probably 3A on a good day.
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donwatson

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Re: machine 'seized' during burn
« Reply #17 on: August 16, 2019, 01:23:48 PM »
@ Zax, I will reconnect the resistor tomorrow, maybe solder this time.
@ggallant571, would I be better with a 12V 6A supply ?? also is this supply ok for the board with + in the middle and - on the outside, or doesn't it matter

thanks again
Don W

ggallant571

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Re: machine 'seized' during burn
« Reply #18 on: August 17, 2019, 08:05:38 AM »
As a rough guide I use:

  NEMA17                8watts
  2,5W Laser Diode      17W (15% efficiency)

For a 3 motor fixture that comes out to 41W. A 60W supply should be sufficient. The problem is none of my EBay 60W supplies can deliver 40W for even 2 minutes.

I don't understand the -/+ question. Our typical controller with the 2.1mm modulate power plug has GND on the outside and +12 on the inside.
« Last Edit: August 17, 2019, 08:23:19 AM by ggallant571 »
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donwatson

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Re: machine 'seized' during burn
« Reply #19 on: August 17, 2019, 12:01:41 PM »
Thanks George I will get a new updated power supply. The outside GND is what this one supplies.

Don W