Common caps for two escs?

[CraigP]

Hello Craig, I can wait for the design of the mixer and build it. Some components can be found in my city. I could try with one to see how they work.

I don't think you can build the mixer. It is a small, microprocessor design. I'm building the optoisolator like you have. I won't have a schematic for the mixer.

[CraigP]

So you guys are good with the off-the-shelf isolator?

[golfito]

Ok, I had not understood correctly.
I could buy one by ebay later.

[golfito]

I am surprised that there are so many threads about erratic failures in RX / TX and not so much information about how to use an OPTO circuit in the RX / ESC.

[TRUCKPULL]

https://www.ebay.com/itm/DasMikro-RC...9479292?_ul=AR

Mix Ratio could be adjusted from 33% to 100%.

33% is the lowest setting.--- Not low enough.
We need below 10%.

Larry

[golfito]

Understood, thanks for the clarification Larry.

[CraigP]

Just to be clear, that’s 33% at 100% rudder input, to either side. I use D/R Reduction on my rudder, usually about 35%. I do that by making the crank arm larger on the rudder servo and use a smaller arm on the rudder. This brings the range to about 12% after the linkage ratio is in play.

I have one on my single Cat, where I just want some speed break heading into the corner. Only good for oval, right turn only. Let’s me run full throttle and allows me to concentrate on rudder only.

These things can be manipulated any way you want! It’s up to individuals to “see” their entire system, and bring each component into compliance to make that vision a reality.

[golfito]

http://www.mtroniks.net/prod/RC-Accessories/WTail.htm


http://www.mtroniks.net/prod/RC-Acce.../Progmixer.htm

[CraigP]

I don’t think the WTail Mixer will work. It has no adjustments that I could find in the manual.

The Progmixer has programming, but I’m not following the directions well. I would have to try one to see.

[CraigP]

I am surprised that there are so many threads about erratic failures in RX / TX and not so much information about how to use an OPTO circuit in the RX / ESC.

Yes, lots of unexplained failures. Many blame the ESCs. Probably, some ESC’s are more prone to signal glitching that others, I’m sure that’s a true statement. I’m beginning to think that all of my boats need isolation on LV ESC W/BEC. I don’t use ESC’s BEC for Rec/Servo power. Others have posted that some go into current limiting and that’s a big problem!

I’ve also been taking a closer look at the UBEC I got from OSE. It is not an isolated output. Has great current output. But it will carry the ground noise from ripple right into the Rec. A better choice is to use an isolated output, that is galvanically isolated from the power input, which is the noisy battery.

[CraigP]

Here’s my single opto-isolator. I’m going to put it in my DF29 Mono, that has a Turnigy 180A ESC W/BEC. Right now it’s running on that BEC, I need to get an external BEC.

[CraigP]

Here’s the dual isolator with the single. Golfito, this is more like what you need, according to your description. Saving this little baby for the dual build sometime this year!

These are using PS2501-1-L-A, a Panasonic version of the 4N25 that Golfito used. I used 0805 SM resistors and added a .01uF bypass cap, it was laying in front of me.

[golfito]

Excellent!
Very small size

[golfito]

I do not have smd resistors. Only 1 / 4w of wire.
I can gain space if I only use 220ohms. And not the sum of 220ohms + 33ohms to get close to the 249 ohms of the specifications.
But I'm afraid to degrade the circuit.

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[CraigP]

You can use 220 Ohm. I built mine with 232 ohms, I had them handy. Especially with a separate channel driving each isolator. You can gain space by mounting resistors vertically. Stick the lower lead straight into the hole, then bend the upper lead down, parallel with the resistor body. Then each resistor takes just two holes.

[golfito]

Great!

[ray schrauwen]

So you guys are good with the off-the-shelf isolator?

I suppose. Knowing now what you have found about ripple coming through, not so much.

Nice circuits. It's a skill I wish I was much better at.

[golfito]

I thought I could add some small capacitors between the + and - cable. C: 100mfx16v

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I have to make the bridges and the welds still.

[CraigP]

That’s way too much capacitance. It only requires .01uF, because the opto uses so little current. Large caps causes current spikes on power up, so you want to watch that. It could put the BEC’s in the ESC’s into current shutdown. The ceramic type cap, value .01-0.1uF, will be best. Sorry to tell you, but you want it right. The layout looks great!

[srislash]

Golfito... you are exhibiting some mad skills. You have a passion for this.

Craig I put in my cancellation of order request with Mtroniks so we shall see. I think at current moment I only would need to set up my BlownAway twin with isolation.
So I could use a dual isolator on that one.

Out of curiosity, would one still need to disconnect the red wire from the BEC equipped ESC’s when plugging in the isolator?

[golfito]

Thank you!
I think I have some ceramic capacitors out there ... the ones I used in brushed 540 engines.

Using the opto plate you must leave the red wires coming from the bec of the esc.

[CraigP]

Thank you!
I think I have some ceramic capacitors out there ... the ones I used in brushed 540 engines.

Using the opto plate you must leave the red wires coming from the bec of the esc.

Yes, each BEC inside each ESC powers up each opto-isolator. So the output signal from the opto-isolator is biased from the supply voltage from each ESC, and any noise is the same, so the ESC runs clean. The input is not wired to the signal (+) on the board, so no need to remove any red wires. The opto-isolator I built is wired like the Futaba servo wiring.

[CraigP]

Golfito... you are exhibiting some mad skills. You have a passion for this.

Craig I put in my cancellation of order request with Mtroniks so we shall see. I think at current moment I only would need to set up my BlownAway twin with isolation.
So I could use a dual isolator on that one.

Out of curiosity, would one still need to disconnect the red wire from the BEC equipped ESC’s when plugging in the isolator?

Shawn, email me your address. The one I built today is yours. I’ll let you know what the shipping is and PM you my PayPal info. Please read response to Golfito, you do not remove any red wires.

Note to Forum: I’m building this has a favor to Shawn, for no sale. He is just covering the shipping. Since the unit is not being sold, I figured this does not need to follow Forum rules for selling items. If I’m in error, then please let me know, thank you.

[golfito]

26910559_1785692478399152_4621563160742118855_o.jpg27021965_1785692528399147_2274054406197546512_o.jpg
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The most similar and according to my friend google ... this one that says 104 would be correct. It is very, very tiny.

[CraigP]

You got it! Perfect size! It’s been so long since I’ve worked with thru-hole parts, brings back good memories...

[golfito]

I discovered that the yellow color means that it is 400v and the 104 equals 0.1mf ... what do you think Craig? I leave these or eliminate them directly ?.

[CraigP]

I discovered that the yellow color means that it is 400v and the 104 equals 0.1mf ... what do you think Craig? I leave these or eliminate them directly ?.

Good to go!

[golfito]

Thank you!

[Jesse J]

Shawn, email me your address. The one I built today is yours. I’ll let you know what the shipping is and PM you my PayPal info. Please read response to Golfito, you do not remove any red wires.

Note to Forum: I’m building this has a favor to Shawn, for no sale. He is just covering the shipping. Since the unit is not being sold, I figured this does not need to follow Forum rules for selling items. If I’m in error, then please let me know, thank you.

Nice gesture Craig! So to put it simply, this unit is still recommended with the set up I attached in post #57?

[CraigP]

Yes Jesse, my simulation results is showing there is a need in all boats, unless you run an Opto-Coupled ESC, like the HV SW ESC’s. The isolation is already in there. I’m finding that sourcing the Receiver power from a BEC inside the ESC is a major step backwards from the days we all ran dedicated Rec batteries. There’s just too much noise at the ESC to make it the common ground. I’m changing my DF29 Mono, with a Turnigy 180 to using an ext. BEC. Then the int. BEC just provides power for the output of the isolator. I think all boat ESC’s should be opto-isolated.

The schematic on Post #64 is for a one input system, where the two motors will always run the same speed. A two input opto is for Chan mixing, with a Trans/Rec that has that capability. Then you will use two channels on the Rec, one for each motor. Also need 2 input for an Ext. Mixing board, such as those posted on this thread.