turbo-s

iTrader: (1)

Thanks PSX.

Community/PSX , which VR voltage regulator is recommended?

quote: "VR to another linear regulator, but low-drop one"

it must be 7805 compatible..

psx

At datasheet for RECOM R-785.0-0.5 You can read that input voltage should be in range 6.5-34V.
So it will be better to have 3 cells, but You can use cells with less capacity.

psx

For example L4940 5V version. It has only 0.5V voltage drop (this is that low-drop ), so accu voltage 5.5V is enought to get 5V at output.

exaturbo

iTrader: (2)

@losikid67

you have a PM....

Jason.

turbo-s

iTrader: (1)

Let's set the PRICE DIFFERENCE aside. (about 9 bucks!)

Which one is the better choice (for efficiency) and qualtiy


L 4940 V5 very low drop 1,5A regulator Case: TO-220 (about USD 1)

or

SIP 3 Recom International R-785.0-0.5 (about USD 9)

thanks

turbo

ratrod0

just got a GT3B for christmas no CD in mine. what does the duel rate do and what do you use it for?

beemerfan

iTrader: (39)

Dual rate decreases the overal throw of the steering servo. When you setup a car, you should set up the left/right travel of the steering to the maximum mechanical limits with the dual-rate set at 100%. Then if you find the car oversteering, you decrease the dual-rate down to limit the steering and help control the car.

hayabusafmw

iTrader: (5)

is there a way to use the GTB3 with a Losi comp crawler???? with the dig???

MMor101

iTrader: (8)

I just got a fully modded GT3B (0.4.1 firmware) and there seems to be some lag in the radio response. I'm coming from a Spektrum system so I figured the frame rate would be similar. Will there be a firmware update with a 5.5ms frame rate like Spektrum? Also, does anyone know of a good replacement for the stock rubber on the wheel? I'd like to put on a softer foam grip on the wheel. Will this radio bind with any other receivers?

pede_187

iTrader: (1)

Hello,

I run a GT3B radio and receiver and I was thinking about running 7.4v into my servos with a BEC but my concern is that if I run 7.4v, I may blow the receiver. Does anybody know if the receiver will handle 7.4v and has anyone done this?

Thanks.

WindDrake

iTrader: (13)

7.4v will roast the RX. The flysky stuff isn't HV capable.

The L4940 is a Linear Regulator (Low Efficiency). The Recom R785 is a Switcher-in-a-can (High Efficiency). Personally, I'd use the Recom. Better battery life.

beemerfan

iTrader: (39)

The frame rate topic has been discussed at length in this forum. You can see most of the questions and answers that were posted by simply searching "frame rates." The bottom line is that they cannot be improved unless changes are made to both the radio and receiver and that isn't likely to happen any time soon. Maybe the next release from Flysky will be better.

This radio will only bind with Flysky receivers and their HobbyKing counterparts. But you can use the 3, 6 or 8 channel receivers. The 3 channel receivers are the cheapest out there for any radio, so go ahead and stock up when they are available.

I used the foam from an aftermarket wheel made for an Airtronics radio. It works well. There are a lot of options for changing the wheel / foam. Try a search in this forum to find those topics. There is even one guy out there custom molding some interesting silicone wheels.

MMor101

iTrader: (8)

Thanks for the feedback. I guess I'll just have to adjust my own internal frame rate lol. It was getting less noticeable throughout the night of racing.

nightmechanic

The L4940 requires much more output capacitance (22uF)than the stock 78M05 (0.1uF), as most Low dropouts do, for stability reasons as far as I recall.
does anyone know if there is a large enough output capacitor on the board? (which would surprise me as i would imagine that any $ conscious manufacturer would not put extra/expensive components with no real reason).

If the answer is no, then the L4940 needs to have an additional cap mounted between its output and ground terminals - not the end of the world and, in my opinion required. (there are probably ceramic 22uFs that can fit in nicely)

in any case +1 for the RECOM as well unless you really need the low voltage.

elex300

iTrader: (110)

I have to disagree on running 7.4v to the receiver. Eventhough the reading for the receiver says 6.6v it's not true. In both of my 1/10 and 1/12 pan cars we have to use receiver packs since we run on 1s lipo's. On the 10th scale I run a 2 cell life pack 3.3 per cell,which fully charged is 7.2v. In the 1/12 i run a 2s lipo rx pack 3.2v per cell and 8.4v at full charge. Been doing it for at least a year trouble free.