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Resistor vs Regulated Pixels


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Posted

Confused a bit. Just been made aware of Regulated Pixels and wondering what I should consider. I have been using resistor type addressable pixels and have had no issues. Ray Wu on aliexpress has free shipping for the regulated pixels...not much of a difference in price TOTAL...I understand the regulated pixels cost more. But what are the advantages/disadvantages? I only read the resistor type are more forgiving if wrongly wired. Insight on this issue please. Thanks for your expertise.

Posted

Reality for our purposes is it really does not make much difference.  As always with pixels, it is far more important that all the pixels for each prop be bought together so that the color match is largely the same.

 

Posted

Just to confuse you a bit more. Regulated nodes still need resistors to set the light balance between R=G=B

What regulated node ALSO do is  start with the same , constant (individually regulated) voltage at each node, so color/intensity in more uniform.

BTW Dumb nodes also have the same resistors, for the same reason: color balance

Posted
58 minutes ago, TheDucks said:

BTW Dumb nodes also have the same resistors, for the same reason: color balance

And current limiting.

 

Posted
56 minutes ago, k6ccc said:

And current limiting.

 

You are correct. different values  just do the balancing.

Posted (edited)

Resistors add Heat and thus create resistance to the flow of energy by increasing Draw

Edited by Jimehc
Posted
5 hours ago, Jimehc said:

Resistors add Heat and thus create resistance to the flow of energy by increasing Draw

Maybe out to lunch here, but this doesn't follow  ohms law  of E = I * R    I and R can't both go up for a given voltage??????

  • Like 1
Posted (edited)

Does a Bulb add resistance to current flow? does a resistor add resistance to current flow... Is heat a by product of resistance to current flow?

As resistance is added into a parallel circuit there is a voltage drop (increased draw) - by removing the resistance the given voltage drop is less at any given bulb

Asking for a friend...

Edited by Jimehc
Posted

Resistors dissipate heat because the are impeding voltage.  The voltage has to go somewhere: Heat, work or light

Kirkoffs law  accounts for currents in parallel circuits Each resistor has its current flow (I dislike using draw. That implies activity. Resistors are passive)

 

Posted

 

1 hour ago, Jimehc said:

Does a Bulb add resistance to current flow? does a resistor add resistance to current flow... Is heat a by product of resistance to current flow?

As resistance is added into a parallel circuit there is a voltage drop (increased draw) - by removing the resistance the given voltage drop is less at any given bulb

Asking for a friend...

Heat is a by product, and depending on how much heat it needs to dissipate the size will differ (to be clear not resistance, wattage) 

This web site also does not agree with you statement.

I'm to lazy to show math, but here is the equation. 1/((1/R1) + ((1/R2)) for equivalent resistance.


Example 1:  Two 50 ohm resistors in parallel is 25  ohms for equivalent resistance .

Example 2:  50 and 60 ohm resistors in parallel is  27.2727  ohms for equivalent resistance.

(here is a link for easy peasy calculations (https://www.digikey.com/en/resources/conversion-calculators/conversion-calculator-parallel-and-series-resistor)

As the TheDucks stated, and I agree with 100% on:   Kirkoffs law  accounts for currents in parallel circuits Each resistor has its current flow.  (I have also had to draw many a diagram in my past and prove these true). 

Posted

Just to confuse the issue, in general terms, there are two ways that a regulator can drop voltage.  The old linear way is that instead of a resistor to drop voltage, you instead use a transistor to drop the voltage.  Because the transistor is adjustable (depending on how you drive it), you can get the same output voltage regardless of the input voltage or the current flow.  In this case, the transistor is dissipating the extra voltage as heat - EXACTLY the same as a resistor would.

The second way a regulator works is what's called a switching regulator.  A switcher rapidly turns the current on an off and there is a filter downstream of the switching transistor to smooth the voltage out in order to supply clean DC power to the load.  Because the transistor is either on or off at any given instant, there is far less power converted into heat.  However you do have to have the filter, and the regulator itself is more complex.

Dollars to donuts, regulated pixels are using linear regulators rather than switching regulators, so in rough terms, the same amount of current is being drawn from the power supply and and the same amount of heat is being dissipated in each pixel.  You do gain a little in being able to deal with more voltage drop (primarily in long strings).

Note, both of these descriptions are HIGHLY simplified.

 

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