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danh

Updated RCST

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Hi, I'm new, as of today. My background is in programming. But, I'm wanting to learn electronics. (My brother is a EE and I want to comunicate with him better ;) . And, my whole family is either into model or full scale aircraft. So, your kind of projects are very interesting to me :D !!

I went to the electronic store this morning to buy caps for a blown motherboard and also thought I'd buy parts for your servo testor. But, I realized that the 2003 schematic specifies a 4.8V power supply, which was fine when I was using NiMh batteries. But I'm totally Lipo, now. So, do you have an updated schematic that would facilitate a 7.4 or 11.1 battery, with maybe a switch to swap between the two? (All my batteries are two or three cell).

Also, is the info on your FAQ sheet about PIC programmers up-to-date? What is the best low-cost programmer? And, does it come with documentation?

Can't wait to develop the expertise and arrange my schedule to work on the CAM projects. I'm looking forward to launching into those.

BTW, I mentioned that I want to build a servo tester for the experience. But, are there commercial ones out there worth looking at, e.g. more functionality?

Thanks in advance!!

Dan H.

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But, I realized that the 2003 schematic specifies a 4.8V power supply, which was fine when I was using NiMh batteries. But I'm totally Lipo, now. So, do you have an updated schematic that would facilitate a 7.4 or 11.1 battery, with maybe a switch to swap between the two? (All my batteries are two or three cell).

With your LiPO powered R/C setup, you are using an ESC with a built-in BEC (or standalone BEC) that regulates the voltage to about 5V. So under the hood, the commonly used 4.8VDC R/C power is still there. It just isn't in the form of a 4-cell NiCd or NiMh. It's now a voltage regulator.

So, if you want to use the RCST on a 2S or 3S LiPO then you'll have to include the function of the BEC. So just download the data sheet to a LM2940T-5.0 Vreg IC and incorporate it into the project if you want to run the RCST directly on LiPO's.

Also, is the info on your FAQ sheet about PIC programmers up-to-date? What is the best low-cost programmer? And, does it come with documentation?

Honestly, I have no idea. I haven't had any reason to buy/test/report on the low cost models. So, what you read on the FAQ is all I know.

are there commercial ones out there worth looking at, e.g. more functionality?

There are a couple dozen commercial servo testers on the market, including some with digital readouts to display servo pulse timing. {Google will help you find them.} Because it is possible to buy a low end servo tester from China for under $10 + shipping, the RCST project would only be of interest to someone that wanted to build one for the satisfaction that comes with working on DiY projects.

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Thanks so much for your quick reply. I'll need to chew on the first one a little. I was thinking that it was just a matter of adding in a couple of resisters to drop the voltage down. But, I'll research the LM2940T solution.

And I'll 'google' for low cost servo testers. But you're right, this looks interesting to me because it's something I'll use and it looks simple enough that I could cut my teeth on it.

Thanks again.

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With your LiPO powered R/C setup, you are using an ESC with a built-in BEC (or standalone BEC) that regulates the voltage to about 5V. So under the hood, the commonly used 4.8VDC R/C power is still there. It just isn't in the form of a 4-cell NiCd or NiMh. It's now a voltage regulator.

So, if you want to use the RCST on a 2S or 3S LiPO then you'll have to include the function of the BEC. So just download the data sheet to a LM2940T-5.0 Vreg IC and incorporate it into the project if you want to run the RCST directly on LiPO's.

hi i'm building RCST for 6s lipo. What do i need to change beside LM2940t-5.0? i'm noob at these thing, i'm that kinda guy with DIY spirit but no skill. :)

my ESC have BEC switcher, but beeping because no receiver/tester connected.

do i have to modified the BEC cable from the ESC.

this is my ESC BTW;

http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9328&Product_Name=TURNIGY_K-Force_100A_Brushless_ESC

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No changes are needed. RCST is compatible with the 5V BEC in your ESC.

Only ESC's without a BEC need a voltage regulator like the LM2940. Your ESC has a 5V BEC so all is fine.

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