Asked — Edited

V4 Servo/Sensor Power Board

Hello everyone:D

I know that the V4 has a direct voltage input from the battery to the digital pins. I was unsure however if this also incuded supplying direct voltage to the outer pin as well?

I was looking online to make something to where i can run my servos and or sensors at a different voltage then what was supplied from the board. I planned to run 12 volts into the board but realized I would need to step down the voltage in every pin that requires 7.2 or 5v. servo City sells a servo Power Board for around $20-30 and I was wondering if anyone had experience with using it. I think it may solve the problem of powering multiple pins at another voltage than what the board is supplying? It says that "cleanly power your servos on more than 6 volts and not burn up your receiver" I could be completely wrong in thinking that this may work so any thoughts would be welcome! It would definitely be a easier way to power things if this could work though

servo power board


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I like this... You could use that to power all your sensors that use 5V as well... Just use a ample 5V power supply in and the rest is plug n'play... I actually might buy a couple for this very purpose.... good find...:)


I built a switched 5vdc supply to power all the sensors that I will use to connect to the EZB4 by using a small blank pc board, a switched regulated power supply that has a variable output, up to 3 amps. The dc input can be from 3.4 to 30 vdc and the output can be adjusted from 3.3 to 28 vdc depending on the actual input and a 8 pin section of a header strip. All these goodies can be found on ebay or Amazon.

User-inserted image


I also found a fused tamiya connector. obviously the tamiya plug can be replaced for the micro deans that the v4 comes with but this would allow us to get rid of the larger power box

fused tamiya plug

@Robot-Doc that is really cool! much like i was going to try to achieve but i think mine would have been 2 separate pieces...


Rich has made a DYI on a servo power board on one of his threads if you're looking to go a cheaper route and make it.

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@Troy do you have a link by any chance

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Details of it are in my Melvin project somewhere. I'll dig out the info... here we go

It's more of a distribution board than a power board though. Very simplistic!


thank you for that link Rich! that is actually pretty simple to just make yourself... :)

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Yep. You could use pin headers too so that standard jumper wires can be used. In my example I soldered direct to the board but I've since changed how I wire things so pin headers are now the better option. I use something similar for I2C distribution on my V3.


Ok... So if I understood... The V4 have no power regulators ? So if I use a 12V font to power it, I can not plug the 6v servos straight to V4? I have to use external power or feed the Ez-b with only 6v?... That's it?

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Correct, the Vcc of each digital port is equal to the input voltage. Therefore you must use a power source that will work with your servos (5v, 6v, 7.4v depending on the servo), use a regulator to reduce the voltage of the digital port or have an external power distribution set up to provide the required voltage.

Be aware, sensors are likely to be 5V. The EZ-B will nag you that your battery is low if you supply it with 5V.

There are regulators on the V4 however these are used for the EZ-B components, as far as power out is concerned there is no regulation (there is a max and min voltage for the V4 though! 4.5v and 16v respectively) but I thought it best to just mention these regulators for a complete answer.


Rich, can't you change the "low" voltage warning threshold in the connection dialog settings? Currently the default is 6.6V...But, can't you just set that at 4.5V or something? Maybe that would eliminate the low battery warnings if powering the EZB with only 5V?

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Yes you can but only after the EZ-B is connected to ARC. So on power cycling it would nag again. Altering this is not something I have tried since I use a 2S LiPo so it's set up fine for default. I'm unsure if the warning resets to the new, lower value on re-connection or if it needs setting each and every time. I'll check when I get a moment.


like rich said each time you power up it will say the voltage is low..

My plan around it is to supply the v4 with 7.2-12volts from a lipo battery and then split off power for sensors, led's, etc

im just making sure but isn't the signal wire still regulated?


Yes, the signal pin is regulated... 3.3V (5V tolerable) if I am not mistaken...


@RichardR, the Vin Default Low Battery Warning is 6vdc not 6.6 vdc but Whats .6 among friends? ;-)

I really dislike that nag phrase. I'm supplying 6.5 vdc to EZB now and something somehow fluxed with the voltage input of my robot and the hag keep nagging me about voltage. I had to power cycle to shut her up. mad

I really wish the battery tender settings were adjustable through the web interface to the EZB hardware instead of ARC.


Hey Guys, it truly is 6.6VDC, i just haven't had a spare moment to update the datasheet, sorry.


I am very confused. I was going to power my EZBs with +12volts from the wheelchair batteries.

Now, I have to go 7.2v or 6volts (what ever it is for the 995 servos.) for the EZB3s.

And ? for the EZB4. ?

I am not sure I understand what you are saying. Is the 6.6 the minimum you can go before the low battery alarm? because I have lots of sensors that require 3.3-5V.

Here is what I have:

I have plenty of regulators. I have a +12 supply from the wheelchair. I have 13 995Metal servos,arms,neck and sonar. 6 or 7volts, I don't know. I have a sabertooth 2X25 for the wheelchair motors, I have two EZB3s and a EZB4. Millions of sensors.

What do you recommend?

confused confused confused

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you must use a power source that will work with your servos (5v, 6v, 7.4v depending on the servo), use a regulator to reduce the voltage of the digital port or have an external power distribution set up to provide the required voltage.

You must either supply the EZ-B V4 with whatever voltage your servos need. Use regulators on the VCC pin of each digital port. Provide an external power source distribution for sensors/servos.


If I set it to 5 volts or 6volts, will that trip the low voltage warning?

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If your VIn (supply to the EZ-B) is below the low battery warning level then yes. If you use regulators on the VCC pins or use an external power distribution method for sensors and servos then no.