New Jarduino build gets started

[ScubaSteve]

Shot in the dark but... Did you order any extra LDDs? Long story short, I need three more. I'm going to be putting a mouser order through but thought I'd ask!

[daplatapus]

I did get a couple extra's, what size did ya need?

[daplatapus]

WooHoo! I got my LDD drivers today and my HLG drivers as well. Man, I didn't think these LDD's were quite that small.








Hey Chis (Chatouille) PM me your details and I'll send you those drivers you needed.

[ScubaSteve]

Ha! And I didn't think that HLG would be so big! It's huge!

[daplatapus]

Haha, yeah, it's gonna take up some space, especially considering I'll have 3 of these 42V's and a 36V.
Well, I couldn't resist doing something since I'm home sick with the flu today. I get bored pretty quick, lol.
I soldered up one of my boards with the mounting clips for the LDD's and everything looks good.


I'm wanting to steal a bit of power from my power supply units so I got some HRD DC converters. But they come stock with set resistors and I want to switch them out for variable ones so I can adjust the voltage I need depending what I want to power up. For instance my Arduino , my cooling fans, etc.
So here's the converter I have:


and the back:



and the variable resistor I'd like to use:



Any insights as to how to wire the variable resistor is greatly appreciated.

[ScubaSteve]

That's pretty straight forward. It's basically the same ideas as the LM2725-ADJ that I'll be using the step down from 24 to 12 V all bundled with an inductor into a nice little package. Basically by varying the value of the two resistors you can change the output voltage, mainly the resistor connecting pin 6 and pin 7. That said both resistors play a role. I tried looking up the datasheet for that converter and it is fantastically ****ty (from a Chinese manufacturer - nuff said). They have an equation for calculating the output voltage based on the resistor values but it seems to be on crack. I'll run through the math and see if I can clean it up and make some sense of for you, then give you a graph of the resistor values versus output voltage.

[daplatapus]

Hmmm, I kinda figured it wasn't great. Here's the unit I bought on ebay:

http://www.ebay.com/itm/HRD-Series-C...item3a67dc22c9

Not sure if that gives you any more info than you had already.

[Chatouille]

Originally Posted by daplatapus

Well, I couldn't resist doing something since I'm home sick with the flu today. I get bored pretty quick, lol.

lol... I'm sure the package of goodies made the decision to stay home easier.

Let me know how those HRD's work out, and how warm it gets. ( I Ended up going with a LM2576HV instead )

When you get a chance, pm me so I can get payment out to you.

[daplatapus]

I finally got to sending them your way today. And PM'd ya with the specifics.