Powerful Chinese KT controller for electric bike (60 V 60 A) — we understand with wires


Hello friends!

This article will be useful to those who collect a powerful electric bike with their own hands, as it will be about a powerful controller.

Among Chinese electrical manufacturers for bicycles is quite common is KUTENG. These controllers are labeled, which starts with «KT», in this case — KT60SVPRCDK, so they are most often called «KT controllers».

In most cases, these controllers have a set of wires at the output, in which not everyone will discern somewhere. Nevertheless, the purpose of the wires usually provides the seller, or they can be found on the Internet.

But the problem lies in the fact that in such a form of the wires are not protected from external conditions, and the controller will have to be hiding into a hermetic case so that the contacts are not oxidized.

And if the controller is closed in the case, then either it will overheat, or it will have to be used not at full power. Ideally, the controller must be placed outside and cooled by the incident air flow. For this, he needs hermetic connectors and protected wires, so moving on.

It’s time to open the controller and look inside. But first you need to discharge the capacitors, and it is best to do this by closing the red and black feed wire through the resistor. Next, we unscrew the end covers — on 5 screws on each side.

After removing the top cover, we see the controller card and 18 power transistors pressed to the cooling housing using 9 plates with holes.

To release them, unscrew the cross-shaped 9 screws from the outside, after which you remove the fee.

Now let’s deal with wires. The thick rectangular connector for connecting to the engine is the wires on the Hall sensors.

Yellow (C), green (b) and blue (a) — signals from the sensors of the rotor position sensors, and white (x4) is a signal from a speed sensor, it is often combined with a thermistor. Red (H) and black (g), respectively, the power of the sensors, voltage of 5 V.

The 5-pin flat connector is designed to connect the display. He has yellow (Rx) and green (TX) — these are wires for transmission and receiving data, black (G) — «Earth», red (N) — Battery voltage and blue (DM) — the inclusion signal.

In order to start the controller without a display, it is enough to close the blue (DM) and red (N) wires. Actually, this is engaged in the display when you turn it on with the button.

Power wire controller — thick red and black — have at the ends of the terminal. But since we will connect the controller to the battery with the XT90 connector («Mom»), we will need a response connector («dad»).

Phase power wires on the engine are also terminals, we will replace them on XT150 connectors, which are much more convenient and faster, but a little later.

We drop from the signal (thin) wires from the board, which go to the engine and on the display. I always pre-post photos, it allows you to avoid mistakes when the new wires are sprinkled.

Yes, the gas handle go blue (TS, signal), red (TV, + 5V) and black (G, «Earth») wires, and on PAS sensor — yellow (zl, signal), brown (ZV, + 5V) and Black (G, «Earth»).

Now about the wires on the brake sensors — they are easier to distinguish them, as they are often dual, that is, parallel. In this case, each sensor of the brake is 2 wires — black (G) and yellow (S). Black is the «earth», and the yellow is alarm, on it voltage 5 volts. With this scheme, the sensors are a conventional button that closes these two wires.

There are still brake sensors in which the Hall sensors are used. In this case, a 3-wire scheme is used, which is added another wire — to power the Hall sensor itself. On it voltage +5 V and it can not be closed with «Earth». The Hall sensor works when the magnet moves past it. More details about the brake sensors can be read in

But back to the controller board. The remaining two-contact connector (Lig) is designed to connect the headlight. It serves a battery voltage when it is turned on on the backlight display (prolonged pressing the «Up» button on the KT displays).

For clarity, I prepared a decoding of the KT controller designations — perhaps someone will be useful.

Now clean the holes from the solder and we carry the cables: 8-wire to connect an integration cable that combines all wires running on the steering wheel (for display, gas handle and brake sensors) and 6-wire to connect the engine hall sensors.

These Wires of the Chinese manufacturer JULET are sealed, and therefore do not oxidize over time, which means they will serve for a very long time.

On force wires, such as the wires of the controller and the phase wires on the engine, wear a glassized tube. It will provide additional protection. To phase wires, we sweep the XT150 connectors and mark the color heat shrink tube.

Before closing the case, it is worth fixing the cables from the inside of the controller from random twitching with the help of nylon clamps and thermoclauses. It will also improve tightness.

As a result, we got rid of terminals on the power wires, and the signal was protected from external conditions with the help of reliable hermetic julet connector.

Now the controller can be installed outside, and it will not overheat, due to the cooling of the airflow, and therefore be able to work at full power.

In conclusion, I will add that a detailed article will be released on the channel about the assembly of a lithium-ion battery with your own hands.

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