1 Topic by BFresh

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Topic: Fluctuating power?

When printing I have noticed that the lights on my SD3 fluctuate in brightness as the bed or hot end is heated. This would indicate that the printer isn't getting enough power right?

I recently replaced the heat pad (as mine had burnt out) along with the power supply, and thicker wiring as required, following the post on here about replacing the heat pad (including soldering on the jumper cables for the MOSFET).

The power supply I used is a cheap 500w PC power supply I had spare. I checked the ratings of it and the 12v supply gives out a maximum of 20A.

The new heated bed gets up to temperature in about 20 to 30 mins. It's one like this (can't find the actual listing for mine) http://www.emakershop.com/browse/listing?l=725

Any ideas?

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Fresh Design Works (UK)
www.freshdesignworks.co.uk

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2 Reply by wardjr

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Re: Fluctuating power?

It does sound like you have a shortage of available power.  If your power supply can only deliver 240 watts maximum I would figure out the wattage of your bed heater.  Grab another power supply to test with.  I have run my printer with a battery charger as a test.  It worked fine when I ran it on the 50 Amp setting.  Make sure if you do this that the charger isn't putting out much more than 14 volts.  This should just be a test, I have run several hours with this setup when my printer showed up with a bad power supply but I wouldn't recommend it.

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

wardjr's Website

3 Reply by satman49

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Re: Fluctuating power?

How about using a 12v car battery?  I use that on my Arduino project.

SD3, E3D hotend,linear bearing on x/y axis',pillow block bearing on y conneting rod, ball bearngs on front y axis, fan on y stepper motor.

4 Reply by wardjr

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Re: Fluctuating power?

satman49 wrote:

How about using a 12v car battery?  I use that on my Arduino project.

Yep that will work but you car wont run as well big_smile.
I actually ran a charger on a smaller ATV battery as a bit of a sink to keep the voltage in line.

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

wardjr's Website

5 Reply by spapadim

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Re: Fluctuating power?

LEDs always flicker. Maybe your new heater generates more electrical noise.  I think LED strip is connected straight to 12V without any filtering circuit, so flicker is normal.

6 Reply by wardjr

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Re: Fluctuating power?

spapadim wrote:

LEDs always flicker. Maybe your new heater generates more electrical noise.  I think LED strip is connected straight to 12V without any filtering circuit, so flicker is normal.

Although flickering as very common I wouldn't go so far as to say "Always".  Mine don't flicker and I know a big part of that is from running my bed through a relay and separate power supply in my case AC.  However before I switched to the AC bed I could dramatically decrease my heat up times with a substantial increase in power availability via battery and charger.  As a real positive side effect my LED's no longer flickered.
If you are starving your LED's for power just imagine what everything else in your system is up against.  I have found that the whole printer just works better with adequate power.

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

wardjr's Website

7 Reply by spapadim

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Re: Fluctuating power?

Perhaps -- I'm no electronics expert. Adrian once suggested he could bore everyone to tears about why LEDs flicker, but unfortunately never elaborated further. smile

FWIW, my clamp meter on my SD2 with everything stock except E3D peaks at about 8A (with stock hotend should be a few amps less, maybe 5?).  Doesn't seem power-starved to me, but it still flickers very noticeably (and it did before the E3D as well).  Also just noting possible alternative explanations: battery could be acting as huge filtering capacitor (esp. if primary source of noise is heater -- perhaps heater coils have nonnegligible inductance? dunno...).

8 Reply by wardjr

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Re: Fluctuating power?

spapadim wrote:

Perhaps -- I'm no electronics expert. Adrian once suggested he could bore everyone to tears about why LEDs flicker, but unfortunately never elaborated further. smile

FWIW, my clamp meter on my SD2 with everything stock except E3D peaks at about 8A (with stock hotend should be a few amps less, maybe 5?).  Doesn't seem power-starved to me, but it still flickers very noticeably (and it did before the E3D as well).  Also just noting possible alternative explanations: battery could be acting as huge filtering capacitor (esp. if primary source of noise is heater -- perhaps heater coils have nonnegligible inductance? dunno...).

All very possible points maybe we will get lucky and we can get Adrian to chime in and bore us to tears big_smile

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

wardjr's Website

9 Reply by BFresh

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Re: Fluctuating power?

Thanks for all your input. I haven't had the time to investigate this further.

Other than the flickering LEDs it appears (I emphasise the word appears) to be printing ok. I am just a little concerned.

The output info on the power supply info is on the attached photo, just in case I got something wrong.

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Industrial Designer
Fresh Design Works (UK)
www.freshdesignworks.co.uk

BFresh's Website

10 Reply by waagstrom

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Re: Fluctuating power?

A problem with "Cheap" PC power supplies is that the 20 amp rating doesn't mean it can sustain that load under normal operating conditions.