redbird300
01-16-2011, 07:26 AM
Well, I decided to start a new thread about this subject, some scale flyers might be interested.
Here is the first post from another thread, and I'll continue the story below this quote:
For those that would be interested in a VERY cheap remote controlled LED driver, which can be switched on/off by means of a TX switch, but also be controlled in brightness by any TX channel if you wish, here's a nice article how to do it yourself:
http://www.zerorc.com/how-build-servo-led-driver
I just build a very dirty and quick prototype, using the circuit board of an old and stripped Towerpro SG90, and tested the device with several channels and switches on a DX7/AR6200 combo, and it works great. Should build a final one now, with several LEDS and in a nice protected and much smaller package, but you get the idea. Enjoy.
Yes, I know, you might find these for a few dollars in some webshop, but this one cost me nothing as I have everything laying around, and it's fun doing it yourself. :YeaBaby:
http://www.helifreak.com/attachment.php?attachmentid=201152&stc=1&d=1294953106
I started working on a more final version of a remote controlled LED driver now. It will be used it in a scale project later on.
Below are some pics, look at them first, but come back to read these notes also:
1) The whole thing will be put in a very large piece of shrink wrap (not the LED contacts of course), but I wanted to show the pics before I did that.
2) I used the circuit board of a larger servo this time, a broken Spektrum DS821, to allow for more current, thus more LEDs. Still need to find out how much the circuit will take continuously before it starts heating up, but the LEDs take only 10 mA a piece, so that should allow for a whole lot of LEDs.
3) The black and orange wire that you see in the pic showing the back of the circuit board, are the wires that went to the servo motor. Well, I used thicker wire, but that’s where the motor was connected. They bring + and - V to the two contact strips.
4) The 5 kilo-ohm potmeter from the original servo has been replaced by 2 fixed resistors (2.2 and 4.7 kilo-ohm), look at the left side of the board, you really need a soldering iron with a very fine, needle like tip !
5) The little project has a connector strip at the right side with 2 x 8 connector pins, to allow for 8 LEDs to be separately connected. The normal servo connectors fit, these have the standard 1/10 inch spacing.
6) Last picture: I removed the useless signal wire from the servo connector going to the LED, and did cut the unneeded part of the connector. This will allow the nut and washer around the chrome LED housing to be removed (over the servo connector which is too wide otherwise) when I will need to mount the holder in a fuselage. There are also black plastic holders available.
7) You’ll need a resistor in series with the LED to limit the current, most LEDs take around 10 mA. Some might take a bit more. My resistor is under the black shrink wrap close to the LED, barely noticable. You need to calculate the value of that resistor, depending on the specs of your LED and the output voltage of your BEC. If you would use all the exact same LEDs, you could get away with a single resistor for all LEDs, soldered between the board and the contact strip. Mind the dissipation of the resistor if you do that.
8) Connect the board to any free channel of your RX, and assign a switch to that channel in the TX. No external power supply needed, you’re basically done. Flipping the switch will activate/deactivate the LEDs.
9) You also need to set “travel range” of that channel to maximum, 150% in my case (Spektrum TX/RX), otherwise you won’t get the full voltage from the BEC to the LEDs. This is also a handy way to dim the LEDs, if you would find that they give too much light (with the chosen resistors). An example: with a 5.6 Volt BEC, and travel range at 100%, I got only 3.1 Volts going to the LEDs, but at 150% travel range, this was the full 5.6 Volt. In fact, 3.1 Volts is enough for the LEDs, but I don’t like the idea that I can blow the LEDs up by changing a setting of the TX. So use the full 150% setting, and add resistors as needed, you’ll need to do that anyway in most cases. And it allows for a better spread on the brightness of the LEDs, see below for that.
10) If you have a free proportional channel on your TX/RX, like the AUX3 channel on a DX8/AR8000 combo, you can change the brightness while flying, by turning the AUX3 knob on the TX. Depending on how you connected the two unequal resistors that replace the potmeter, you’ll have control over the LEDs on the low or high half of the channel. The other half won’t change a thing, they will stay in the last position. Not important, but nice to know. Just change the order of the resistors if you regret how it works after having build the project.
11) Use super bright LEDs, you won’t believe how much light these produce nowadays.
12) Dimension are about 5 x 2 centimeter, but as you can see, it could be made a little smaller even, by soldering the resistors straight up, cutting the bottom circuit board, using a separate connector system, etc... Not that important in my particular case, and I preferred mechanical and electrical stability above miniaturization. The weight is 10.2 grams, connector cable included to the RX, but without the LEDs.
In short: I just connect this board to the RX and connect the LEDs to the board.
Tested on the bench in one of my helis, works like a charm. Enjoy. :smokin:
http://www.helifreak.com/attachment.php?attachmentid=201776&stc=1&d=1295182875
http://www.helifreak.com/attachment.php?attachmentid=201777&stc=1&d=1295182875
http://www.helifreak.com/attachment.php?attachmentid=201778&stc=1&d=1295182875
Here is the first post from another thread, and I'll continue the story below this quote:
For those that would be interested in a VERY cheap remote controlled LED driver, which can be switched on/off by means of a TX switch, but also be controlled in brightness by any TX channel if you wish, here's a nice article how to do it yourself:
http://www.zerorc.com/how-build-servo-led-driver
I just build a very dirty and quick prototype, using the circuit board of an old and stripped Towerpro SG90, and tested the device with several channels and switches on a DX7/AR6200 combo, and it works great. Should build a final one now, with several LEDS and in a nice protected and much smaller package, but you get the idea. Enjoy.
Yes, I know, you might find these for a few dollars in some webshop, but this one cost me nothing as I have everything laying around, and it's fun doing it yourself. :YeaBaby:
http://www.helifreak.com/attachment.php?attachmentid=201152&stc=1&d=1294953106
I started working on a more final version of a remote controlled LED driver now. It will be used it in a scale project later on.
Below are some pics, look at them first, but come back to read these notes also:
1) The whole thing will be put in a very large piece of shrink wrap (not the LED contacts of course), but I wanted to show the pics before I did that.
2) I used the circuit board of a larger servo this time, a broken Spektrum DS821, to allow for more current, thus more LEDs. Still need to find out how much the circuit will take continuously before it starts heating up, but the LEDs take only 10 mA a piece, so that should allow for a whole lot of LEDs.
3) The black and orange wire that you see in the pic showing the back of the circuit board, are the wires that went to the servo motor. Well, I used thicker wire, but that’s where the motor was connected. They bring + and - V to the two contact strips.
4) The 5 kilo-ohm potmeter from the original servo has been replaced by 2 fixed resistors (2.2 and 4.7 kilo-ohm), look at the left side of the board, you really need a soldering iron with a very fine, needle like tip !
5) The little project has a connector strip at the right side with 2 x 8 connector pins, to allow for 8 LEDs to be separately connected. The normal servo connectors fit, these have the standard 1/10 inch spacing.
6) Last picture: I removed the useless signal wire from the servo connector going to the LED, and did cut the unneeded part of the connector. This will allow the nut and washer around the chrome LED housing to be removed (over the servo connector which is too wide otherwise) when I will need to mount the holder in a fuselage. There are also black plastic holders available.
7) You’ll need a resistor in series with the LED to limit the current, most LEDs take around 10 mA. Some might take a bit more. My resistor is under the black shrink wrap close to the LED, barely noticable. You need to calculate the value of that resistor, depending on the specs of your LED and the output voltage of your BEC. If you would use all the exact same LEDs, you could get away with a single resistor for all LEDs, soldered between the board and the contact strip. Mind the dissipation of the resistor if you do that.
8) Connect the board to any free channel of your RX, and assign a switch to that channel in the TX. No external power supply needed, you’re basically done. Flipping the switch will activate/deactivate the LEDs.
9) You also need to set “travel range” of that channel to maximum, 150% in my case (Spektrum TX/RX), otherwise you won’t get the full voltage from the BEC to the LEDs. This is also a handy way to dim the LEDs, if you would find that they give too much light (with the chosen resistors). An example: with a 5.6 Volt BEC, and travel range at 100%, I got only 3.1 Volts going to the LEDs, but at 150% travel range, this was the full 5.6 Volt. In fact, 3.1 Volts is enough for the LEDs, but I don’t like the idea that I can blow the LEDs up by changing a setting of the TX. So use the full 150% setting, and add resistors as needed, you’ll need to do that anyway in most cases. And it allows for a better spread on the brightness of the LEDs, see below for that.
10) If you have a free proportional channel on your TX/RX, like the AUX3 channel on a DX8/AR8000 combo, you can change the brightness while flying, by turning the AUX3 knob on the TX. Depending on how you connected the two unequal resistors that replace the potmeter, you’ll have control over the LEDs on the low or high half of the channel. The other half won’t change a thing, they will stay in the last position. Not important, but nice to know. Just change the order of the resistors if you regret how it works after having build the project.
11) Use super bright LEDs, you won’t believe how much light these produce nowadays.
12) Dimension are about 5 x 2 centimeter, but as you can see, it could be made a little smaller even, by soldering the resistors straight up, cutting the bottom circuit board, using a separate connector system, etc... Not that important in my particular case, and I preferred mechanical and electrical stability above miniaturization. The weight is 10.2 grams, connector cable included to the RX, but without the LEDs.
In short: I just connect this board to the RX and connect the LEDs to the board.
Tested on the bench in one of my helis, works like a charm. Enjoy. :smokin:
http://www.helifreak.com/attachment.php?attachmentid=201776&stc=1&d=1295182875
http://www.helifreak.com/attachment.php?attachmentid=201777&stc=1&d=1295182875
http://www.helifreak.com/attachment.php?attachmentid=201778&stc=1&d=1295182875