Feb 8, 2018


Oh so much snow...

I guess snow is a by-product of living in a beautiful state like Michigan. Oh well, camping season starts in 3 months.

By now you should have seen the latest set of 3 videos (and webpages) I published about DC surge suppression. I did receive one comment; that it is not needed due to the RV's battery being a natural surge suppressor. Unfortunately I fat-fingered my reply to the comment and it got deleted. So if you are the person that sent the comment, my apologies. If you want to contact me, I welcome your input.

I have heard that notion several times before; but in my research, I could not find any documentation or study to suggest that is true; in fact, I could not even find anything on the topic (my googling skills being what they are). If such documentation exists, I would like to see it, as I will make every effort to understand the concept.

But if true, why would Lippert, American Technology Components, Norcold, and other RV manufacturers add DC surge suppression to their products? And you know that as "cost-conscious" (cheap) the RV industry is, they would not be adding them if not needed.

And remember, there is even an international standard (ISO-7637) that covers this very topic; surge suppression in automotive systems. And isn't it interesting that my Rigol DG1022 Laboratory Waveform Generator has 11 built-in automotive voltage transient waveforms explicitly for ISO7637 compliance testing of automotive surge suppressors?

The Rigol Arbitrary Waveform Generator can even output EKG waveforms for medical electronics testing! How cool is that?

And finally, why then was I able to detect voltage transients on my oscilloscope when I performed the water pump test on the RV itself? The RV's battery didn't suppress those.

With all of the evidence I discovered that transients exist, and being able to replicate them, I simply have to take a skeptical view that the RV's battery provides any protection.

However, I have an open mind, so if evidence does exist, I will acknowledge it. So if anyone has any white papers or other documentation, please send me the source so I can review it. Otherwise, it seems to me to be nothing more than yet another internet-myth (like the batteries discharging if you set them on concrete myth).

On the other hand, you can make the surge suppressors for just a few dollars each, so what can it hurt? The thing is, how do you know if they are working or not? If the LED doesn't fail, is it because of the suppressors? But if the LED fails, is it due to other reasons; life span, manufacturing defects, etc?

As the Jimmy Buffett song goes;if the phone doesn't ring, it's me...

OK, enough about that... on to more interesting things:

I know I promised more articles and videos will be forthcoming, and I did deliver on the first three this month. Due to the winter season, it is a bit hard to do any video recording in the RV, so I try to balance "technology" articles such as the surge suppression topic with actual projects.

"All about Dimmers" Project

Or perhaps I should rename it "More about Dimmers than you want to know". For this project, I bought about a dozen or so dimmers (which did cost a few dollars), and in conjunction with the Lippert Linc project, even designed my own dimmer.

I then discovered some real issues and unexpected results. For example, some LED puck lights (certified as dimmable)have internal circuitry (LED drivers) that results in a capacitive load on the dimmer. This can cause the dimmer to dissipate heat, and some dimmers are just not made to do that.

So in other words, depending on the LED puck lighting, a dimmer could heat up on light A, and not light B.

And for some dimmers, they could heat up significantly... that is not good.

To test the dimmers, I was using an Electronic Dummy Load, but that piece of equipment is more designed to test power supplies and batteries, and more difficult to use with the PWM (Pulse Width Modulation) output of the dimmer. So I ended up building a dummy load specifically for testing the dimmers, which is one reason this project is taking so long.

A dummy load "mimics" or replaces the actual load (in this case; LED lights) for the device under test (dimmer). For example, the dummy load I am designing can handle 100Watts. Since each of the 4.5in Puck Lights are 4W, I can dial in up to the equivalent of 1-to-25 puck lights to load the dimmer without having to go out and buy them.

If this seems too technical to you - don't despair. I will present the results in a way that is understandable by non-technical people.

More to come;