LED's flashing when Hotend/Bed powered up.

[add1ct3dd]

So, this looks to be a 12v noise issue (you experience the same in the RC world),

I just installed these: http://www.thingiverse.com/make:104811

However, when powering up the bed or hotend, they are flickering!

They're powered via 12v, seperate wires to the RAMBo (using the SATA power connectors), though I believe it's a single 12v rail?

I guess the solution would be to install a capacitor for the LED's? It looks to happen primarily when the hotend/bed are switching, to maintain temp.

Cheers,

Matt

[Eaglezsoar]

So, this looks to be a 12v noise issue (you experience the same in the RC world),

I just installed these: http://www.thingiverse.com/make:104811

However, when powering up the bed or hotend, they are flickering!

They're powered via 12v, seperate wires to the RAMBo (using the SATA power connectors), though I believe it's a single 12v rail?

I guess the solution would be to install a capacitor for the LED's? It looks to happen primarily when the hotend/bed are switching, to maintain temp.

Cheers,

Matt

A capacitor would reduce the flickering but will not stop it. The flickering is caused by the PID of the firmware changing the current to the hotend and heat bed to maintain temperature.
The way to stop the flickering is to use a constant current and voltage module like this one on Ebay:
http://www.ebay.com/itm/5A-Constant-Cur ... 1200620645

I believe that Amazon also sells these modules.
See the module here: http://forum.seemecnc.com/download/file ... &mode=view Thanks to Cambo3D for the picture.

[add1ct3dd]

So, this looks to be a 12v noise issue (you experience the same in the RC world),

I just installed these: http://www.thingiverse.com/make:104811

However, when powering up the bed or hotend, they are flickering!

They're powered via 12v, seperate wires to the RAMBo (using the SATA power connectors), though I believe it's a single 12v rail?

I guess the solution would be to install a capacitor for the LED's? It looks to happen primarily when the hotend/bed are switching, to maintain temp.

Cheers,

Matt

A capacitor would reduce the flickering but will not stop it. The flickering is caused by the PID of the firmware changing the current to the hotend and heat bed to maintain temperature.
The way to stop the flickering is to use a constant current and voltage module like this one on Ebay:
http://www.ebay.com/itm/5A-Constant-Cur ... 1200620645

I believe that Amazon also sells these modules.
See the module here: http://forum.seemecnc.com/download/file ... &mode=view Thanks to Cambo3D for the picture.

Nice one cheers .

Ordered a couple from eBay!

[jdurand]

The reason you see so much 12V noise is the typical computer power supply only monitors the 5V output and keeps that accurate. The 12V is sort of a byproduct of making the 5V. It used to be if you didn't have a 20% load on the 5V supply they'd over-voltage and trip off. I STILL use small DC-DC converters in designs where I have to put a resistor across them as a heater, just to keep them stable. My circuits draw next to nothing when they're idle and power supplies don't like that.

You can also get the analog PID in the power supply confused with pulsing current draw. I designed a board using military grade high end supplies, but my circuit was asleep most of the time and pulsed on for brief bursts of activity. Peak current was well under the rating for those supplies but they STILL blew up.

Now I design lighting controls like dimmers, pulsing 40 Amps out of a 24V supply to drive LEDs has to be done carefully/craftily or you will release a lot of magic smoke.

[Jimustanguitar]

The way to stop the flickering is to use a constant current and voltage module like this one on Ebay:
http://www.ebay.com/itm/5A-Constant-Cur ... 1200620645

I believe that Amazon also sells these modules.
See the module here: http://forum.seemecnc.com/download/file ... &mode=view Thanks to Cambo3D for the picture.

So where is a device like this installed? Do you use it on specific inputs of the Rambo, between the Rambo and accessories, or is it regulating the power to everything?

[Eaglezsoar]

The way to stop the flickering is to use a constant current and voltage module like this one on Ebay:
http://www.ebay.com/itm/5A-Constant-Cur ... 1200620645

I believe that Amazon also sells these modules.
See the module here: http://forum.seemecnc.com/download/file ... &mode=view Thanks to Cambo3D for the picture.

So where is a device like this installed? Do you use it on specific inputs of the Rambo, between the Rambo and accessories, or is it regulating the power to everything?

It is installed between the power and the LEDs

[add1ct3dd]

Yep as above, between the power and whatever you're powering.

I bought a couple, not sure what else I'll use the other one for yet, maybe some LED's elsewhere, perhaps at top pointing down, or an LED ring :]

[Mac The Knife]

And then there are these from Hansens Hobbies,,, http://www.hansenhobbies.com/products/l ... led_cl_10/

[Eaglezsoar]

And then there are these from Hansens Hobbies,,, http://www.hansenhobbies.com/products/l ... led_cl_10/

Those from Hansen hobbies will work but 10ma current is approximately 1/2 of the rated current on most 5mm leds so they won't be as bright as they could be but will
last their rated lifetime. For the price I think they are certainly worth a try.

[jdurand]

You can parallel two constant current devices to get 20mA.

Box, outside, think.

[Eaglezsoar]

You can parallel two constant current devices to get 20mA.

Box, outside, think.

20ma is the maximum rated current for most of the 5mm and below leds and using 20ma to drive your leds would give you bright leds at a reduced life.
Thanks though because even though they would result is shorter life for the leds it is an excellent idea. Thanks for thinking outside the box.

[Mac The Knife]

Well, they do offer 20ma http://www.hansenhobbies.com/products/l ... led_cl_20/

[Eaglezsoar]

Well, they do offer 20ma http://www.hansenhobbies.com/products/l ... led_cl_20/

Thanks for the link. I am learning something also and that is that the members of this forum are great and want to help each other out.
Thanks and Happy Holidays!