Power connectors

Hi all,

I’ve just ordered a Serial 8 controller from a site here in the UK. I need to make some leads to connect my power supply to the board header pins.

So I basically need a 2 socket version of a servo connector, but I don’t know what they’re called. Can anyone tell me what I should be searching for, please?

Thanks in advance,
Ken Pierce.

I’m not sure what you mean by “what they’re called,” but you can run your servo controller off a single power supply in a couple of ways:

  1. If the voltage your power supply produces is low enough, you can connect it just to the servo power pins, and use the Vcc=Vs jumper to power the on board micro controller directly.

What’s “low enough” depends on which version of the serial 8 servo controller you purchased. Some distributors sell the “kit” version of the servo controller, where the microcontroller can handle 4.0-5.5V directly. Others sell the surface mount version of the controller, where the microcontroller can only take up to 5V.

<–Kit Version | Surface Mount Version–>

In either case, this is the only way to go if your power supply produces less than 5.6V for the kit version, or less than 5V for the surface mount version. I’m not so fond of it though, as it connects your power supply straight to the microcontroller, and can potentially damage/destroy it if you do something foolish like brush up against the voltage control knob of your power supply.

  1. If your power supply produces more than 5.6V for the kit version, or more than 5V for the surface mount version, you can simply connect it to both the servo and electronics power pins (but don’t use the Vcc=Vs jumper). I much prefer this setup, because the microcontroller is protected from unintentional (i.e. my fault) voltage spikes by a voltage regulator.

To make a “two socket” version of the board in this case, all you have to do is connect the positive output of your power supply to both of the positive power input pins (one for servo power, one for electronics power, called different things on different board versions). All the electronics share a common ground, so you only need to connect the negative terminal of your power supply to one ground pin, your choice. Remember not to use the Vcc=Vs jumper in this setup!

Anyway, did that help or have I given you way more information than you wanted? Which version of the servo controller did you get, and what are your plans for it?


Hi Adam,

Thanks for the quick reply. I’m planning to make a camera pan/tilt rig using a couple of servos.

That actually answered another question that might have come up about power, but wasn’t what I meant to ask.

I don’t have a pre-built battery pack from a supplier; I literally have a collection of AA cells and some wire. I don’t want to solder the wire directly onto the board, so I want to purchase some female (crimp?) connectors to match the header pins of VIN / VCC (I expect they’ll look much like the connectors for the servo controllers, only with 2 pins).

But there’s a lot of choice out there and having never purchased any before, I’m unsure what to look for. For example, what’s the pitch on the header pins. I also wondered if they had a ‘name’ that would help when searching for them?

Thanks again,

I get you now. The header pins for all the connections, including the servos, have a 0.1 inch pitch, probably the most common in the world. You can scavenge connectors from some old computers or other electronics, but you should be able to find the components to build your own.

You’re right that you have a lot of choices, but (just about) anything with a 0.1" pitch will work for you. For example, Jameco electronics sells “.100 Non-Polarized Connector Housings & Crimp Pins”. With these you buy the plastic connector housings and female pins (little metal sockets for the “male” pins on your board) which you crimp (and add solder if you like) onto stripped wire ends with a special tool, or just pliers. You insert the pins into the housings with a particular orientation and get a satisfying little click.

Digikey sells similar items, but in their terminology these fall into the greater category of “rectangular connectors.” If you don’t fancy buying a special pin-crimping tool (and again, for a few pins, pliers will work fine) there are other “rectangular connectors” or “header receptacles” that require no soldering, you simply press your wires into little forked tines that pierce the insulation and make the electrical connection. Sometimes “header receptacle” refers to a socket that is meant to be soldered to through holes on a circuit board, not to have wires connected to it.

Anyway, it’s really all semantics. Anything you can get your hands on locally with a 0.1" pitch will work. Beyond that I generally just go by the product photos.



The power requirements of the through-hole and SMT versions are basically the same, except for the upper limit on the voltage regulator input. They both use the same microcontroller, so both can theoretically handle up to 5.5V on the Vcc line.

The general category of component you’re looking for can be “female header”, such as Digi-Key part number s7000-nd, which is a 2-pin female header with PCB pins. For servo power, you can also use 3-pin connectors like those on servos. For instance, if you have a dead servo, you could cut off the wires and just connect the red and black ones to your power source.

- Jan


Thank you both for your speedy and thorough replies. I shouldn’t have a problem getting on with the project now :slight_smile: