Turnigy 5 amp (7.5 amp) UBEC

[Old School]

I have sourced several Hobbyking Turnigy 5 amp UBEC for projects. My current project a Hobbyking Osprey will use one of these ubec units. I will use the 6 volt output to power the 20kg force servo for the rudder.

Reading online on this model and several others that are sold under different names (Hobbywing and Hifei) it seems that the 5 amp output is a little misleading under load and apparently under load the unit can become quite hot. One report states to remove the shrink wrap and place the pcb on a cooling plate using heatsink compound. Also states not to use velcro to attach the unit most likely due the heat involved.

Now my question, would the unit in usage actually see such a high current draw, please and would the amperage load be sustained? The input wires are quite a small gauge and most likely are barely sufficient to carry such a load. I have no idea what load the ESC or servo would draw. The report above about sustained heat was under test with a constant load and not a real time event. Am I reading too much into the capabilities of this unit please.

[TRUCKPULL]

I run one Turnigy 5 amp UBEC set on 6v
This is in a twin CAT
2 - 180 -v2 ESC's and TWIN Servo's Hitec Digital HS-5645MG's
With NO problems. I have never seen them get hot.

Larry

[Old School]

Larry,
many thanks. The operator that reported the high temps was doing a test on the unit under a sustained amperage load. In reality maximum current draw would not be sustained.

[Mxkid261]

I also run those same Turnigy UBEC units on 6v and have never seen them get hot. I'll shoot them with my infrared gun from time-to-time while checking other component temps.

[TRUCKPULL]

Also on this UBEC I solder the connection for 6Volts.

I cut off the pin for the 5V connection.
Then bend the two pins a little bit for the 6V connection.
Then solder them.

This is a better connection then the little slide on plug, and no change of corrosion or a loose plug shutting down your power two the radio.
Ask me how I know?

Larry

[Mxkid261]

Also on this UBEC I solder the connection for 6Volts.

I cut off the pin for the 5V connection.
Then bend the two pins a little bit for the 6V connection.
Then solder them.

This is a better connection then the little slide on plug, and no change of corrosion or a loose plug shutting down your power two the radio.
Ask me how I know?

Larry

Larry that's a great idea thanks for the tip. Definitely doing this on mine

[rol243]

Do you guys find using this ubec is better than using the built in bec from the esc ?

[Old School]

Many thanks gentlemen, I like the tip of soldering the 6 volt pins. My ubec, while similar looking is the 7.5 amp model. It will supposedly output 5 amp continuously with a 7.5 amp surge. In reality, as the amps rise the voltage drops from reports.

From my reading a standalone ubec reduces the heat generated by the ESC.

[Bp9145]

Also on this UBEC I solder the connection for 6Volts.

I cut off the pin for the 5V connection.
Then bend the two pins a little bit for the 6V connection.
Then solder them.


This is a better connection then the little slide on plug, and no change of corrosion or a loose plug shutting down your power two the radio.
Ask me how I know?

Larry

Many thanks Larry, that is something I need to do to a couple of mine

[Bp9145]

do you guys find using this ubec is better than using the built in bec from the esc ?

absolutely! ! !

[rol243]

I ask this as my son used to fly r/c helis and they did start using ubec,s to power the 4 x servos but some brands started playing up so they went to small LiFe receiver packs to power servos and receivers direct. this method seemed very reliable.

[Old School]

This ubec, while I have sorted it out, had me a little perplexed. The "On"/"Off" switch does exactly that however, the switch works opposite to how one would think. A switch in the "On" position one would think would imply electrical continuity, however, continuity is only there with the switch in the "Off" position.

I decided to remove the switch and initially thought that the wires needed continuity and soldered them together. Of cause no output from the ubec. When I separated the wires I had 6.2 volts to the receiver. This should be explained in the instructions.

I also as advised removed the 5 volt pin and soldered the 6 volt pins together. Maybe overkill but I waterproofed the ubec with special sealing compound.

[TRUCKPULL]

Tim

There is a bit of an explanation about that here on OSE.
https://www.offshoreelectrics.com/pr...rod=ker-HWUBEC

●If the UBEC is supplied with a switch, it allows the power to the RC components (receiver, servos, etc) to be controlled via this switch. Please note that the “ON” & “OFF” state of the switch are logically reversed with the output state of the UBEC. When the switch is “ON” (switch closed), the UBEC output is shutdown, when the switch is “OFF” (switch opened), the UBEC output is normal. This feature allows the switch to be cut off if it is not needed (saving weight) which allows power to RC components to be controlled in the usual way by connecting and disconnecting the main battery pack. (The switch is optional )

In short if you do -not want the switch, (CUT IT OFF) and the unit works ON when plug in the main Packs, and OFF when the main packs are disconnected.

Larry

[Old School]

Larry,
many thanks. I removed the switch to avoid any issues with water contamination or corrosion on the switch contacts, In reality as no continuity is needed to actually supply power to the receiver then the condition of the switch is irrelevant. Seems illogical to have a switch that is on when off and off when on.

[rol243]

I have done similar mods to my Turnigy 180 esc,s where there is an on / off switch which is only a continuity wiring , so its just a matter of removing the switch and joining both black and red wires together. its a very cheap switch so in time it could fail in its connections.

[Old School]

I have done similar mods to my Turnigy 180 esc,s where there is an on / off switch which is only a continuity wiring , so its just a matter of removing the switch and joining both black and red wires together. its a very cheap switch so in time it could fail in its connections.

The problem is that the Turnigy/Hifei/Hobbywing 7.5 amp ubec switch is the opposite logic to what a switch should be. On the Turnigy when the switch is removed then there must be no continuity between the switch wires or there will be no output. If the wires are joined then there is no output, unlike say the 180 amp ESC switch.