On Wed, Oct 30, 2024 at 03:03 AM, holoma47 wrote:
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I feel that the QMX should have some protection against such short power inerrupts.
This is very important. As the SMPS voltages are controlled only at 1ms intervals, it is clear that the design relies on the assumption that no millisecond-scale power failures can occur.?
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Could it be as simple as adding a suitable large electrolytic capacitor to the pins of the 12V power input jack?
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I'm not at all sure this will help because when there is a power interruption the big capacitor will hold the voltage up for longer so that there is more time for the SMPS controller to react, trying to keep the voltage up. Then when the voltage is restored a lot of current can flow into the SMPS before the controller has had a chance to react.
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Robert's description of his failure conditions - using a battery capable of delivering a lot of current may also be significant.? I'd actively avoid any sort of controllable power supply if I was trying to induce this problem.
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BTW I've seen the 2.5mm vs 2.1mm power plug issue a lot but most power supply circuits don't fail and all that happens is that people complain of things shutting down or running incorrectly.? Computer controlled telescopes had this a lot.
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Chris, G5CTH
