A short guide to wire connectors for UAVs, for interfacing with power/pixracer/ESCs/motors, etc.
Terminology
the pitch refers to the distance from one pin to another.
The wire size (measured in American Wire Gauge AWG) determines the size of the wire that can be accommodated in the connector housing. The higher the number, the thinner the wire.
JST refers to Japan Solderless Terminal, which refers to a family of specific types of terminals. Wikipedia has a detailed list of them. One thing to note is that not all white terminals on a PCB are JST connectors, as we will see below…
Wire to board connectors
| Name | pitch | Current (Amp) | Voltage (V) | Wire size (AWG) | Pins | Lock | Uses | Image |
|---|---|---|---|---|---|---|---|---|
| JST GH (info) | 1.25 mm (0.049 in) | 1 | 50 | 26 - 30 | variable | Yes | Pixracer |  |
| JST SH (info) | 1.00 mm (0.039 in) | 1 | 50 | 28 - 32 | variable | No | Flight Controllers, RC Receivers, Video Transmitters |  |
| Molex Picoblade (info) | 1.25mm | 1 | 125 | 26 - 32 | variable | No | J121 auvidea TX2 connector board, amongst others |  |
| JST XH (info) | 2.5mm | 3 | 250 | 22 - 30 | 3-7 | No | Balance plugs for batteries |  |
| DF13 (info) | 1.25mm | 1 | 30 | 26 - 30 | variable | Pixhawk connector |  |
Wire to wire connectors
| Name | pitch | Current (Amp) | Voltage (V) | Wire size (AWG) | Pins | Lock | Uses | Image |
|---|---|---|---|---|---|---|---|---|
| JST RCY (info) | 2.5mm | 3 | 250 | 28-22 | 2 | Yes | ESCs, LED Strips |  |
| Dupont black connectors | 2.54mm (0.1 in) | variable |  |
|||||
| XT30 | 2mm | 15 | 500 | 18 | 2 | Battery connector |  |
|
| XT60 | 2.5mm | 30 | 500 | 12 | 2 | Battery connector |  |
|
| XT90 | 40 | 500 | 10 | 2 | Battery connector |  |
JST XH
these are almost exclusively now used for the balance plugs on the batteries. The number of pins/wires is X+1 where X is the number of cells. So 2S batteries should have a balance plug with 3 pins, 3S will have 4 pins, etc.
Dupont connectors
The dupont connector are just a colloquial name for black pin header connectors. They are difficult to find, since “Dupont” isn’t the universal name for them.
XT series
the number following XT refers to the max current that can be put through these connectors
How to tell them apart?
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JST GH and Molex Picoblade are often confused as they have the same pitch. However, the GH has a clip that should lock into its housing on the board with a satisfying click, and the Molex Picoblade does not.
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Molex Picoblade and DF13 are often confused as well, since they have the same pitch and looks like they could fit in the same connector housing. However, the DF15 has a row of tiny slits at the bottom of the connectors, and should not fit into a Molex Picoblade housing easily, and vice versa.
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The JST SH should look like a smaller version of the Molex Picoblade, because of the pitch differences.
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JST XH has two clips that are arrow-like at the top of the male connector. Those clips should allow it to snap into the connector housing on the balance board of the battery charger.
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The XT30/60/90 connectors will have its type etched onto the connector, as shown in the photos.
- Sometimes, you just need to stare at all of them at once to figure out which one is yours. The following pictures are shamelessly scraped through the web:
