78S05 vs 7805 Voltage Regulator?

[erik343]

What is the difference between 7805 and 78S05 voltage regulators? I am curios about this because I am RGB modding my NES. I have heard of people replacing the 7805 with a 78S05 on their NES units. Is it better to use the original 7805 or, it is better to replace it with the 78S05 instead?

I noticed that on the NESRGB, they keep the 7805 that is located near the power supply box, and they add another external 78S05 voltage regulator that hooks into the NESRGB 5V pin. I am just curious, and I want to do the job right!

Thanks.

Erik W.

[Jdurg]

I believe the only difference is that a 78S05 can supply up to 2.0A of current while the 7805 is only rated for up to 1.0A of current.

[copy]

I believe the only difference is that a 78S05 can supply up to 2.0A of current while the 7805 is only rated for up to 1.0A of current.

That's right, and the 78S05 is also rated for 150°C versus the typical 7805's 125°C.

What is the difference between 7805 and 78S05 voltage regulators? I am curios about this because I am RGB modding my NES. I have heard of people replacing the 7805 with a 78S05 on their NES units. Is it better to use the original 7805 or, it is better to replace it with the 78S05 instead?

I agree with Bob from RetroRGB's philosophy that there are a couple of reasons to do this:

First, it's a preventative measure, replacing a decades-old regulator with a brand new one that will probably last longer from now than the original.

Second, it provides extra overhead amperage, just in case. This ensures that any add-on hardware (RGB mods, flash carts, wireless controller receivers, etc.) will always have plenty of power.

(In the special case of the SNES, it can also reduce the "vertical line" artifact.)

I noticed that on the NESRGB, they keep the 7805 that is located near the power supply box, and they add another external 78S05 voltage regulator that hooks into the NESRGB 5V pin. I am just curious, and I want to do the job right!

The frontloader NES has a small heatsink on its 7805. When you add the power draw of the NESRGB to it, that 7805 could potentially get too hot. Therefore Tim provides an external 7805 board (not 78S05) solely dedicated to powering the NESRGB.

Some people argue that the second 7805 is not really necessary, but I think it's a "better safe than sorry" kind of a thing. I personally went all-in on my frontloader, replacing the original 7805 with an 78S05, and installing the secondary 7805. I just wanted the peace of mind to know that my NES should be able to operate very reliably for the foreseeable future.

[erik343]

Thanks for the information. I am going to replace the stock 7805 in the NES with the 78S05. But, I will also use the extra external 7805 for use to power the NESRGB.