View Full Version : [Question(s)] PhidgetAdvanced Power Supply, 6V or 12V?

09-30-2008, 08:59 AM
For the PhidgetAdvancedServo Kit 4-Motor, which Power Supply should be used to plug into the controller? A 12V, 2Amp, or a 6 Volt, 1.5 Amp?

Since the servos this controller controls need 6V, It makes me think one would need a 6V power supply as well, but on the robotshop.ca website, the controller comes with a 12V, 2A power supply (link: http://www.robotshop.ca/home/products/robot-parts/motor-controllers/servo-controllers/phidgets-4-servo-kit-2001.html (http://www.robotshop.ca/home/products/robot-parts/motor-controllers/servo-controllers/phidgets-4-servo-kit-2001.html))

On the other hand, at Trossen, it comes with a 6 Volt, 1.5 Amp (link: http://www.trossenrobotics.com/store/p/3190-4-Motor-Servo-Kit.aspx (http://www.trossenrobotics.com/store/p/3190-4-Motor-Servo-Kit.aspx))

Is there a typo, or is something else going on that Im missing?

09-30-2008, 10:01 AM
I'm not entirely sure it has an onboard voltage regulator, I can check for you when I get into work.

If not- 12v will fry your servos very quickly.

09-30-2008, 10:13 AM
I have had students use 12 volts on a phidget 4 in a pinch. It got hot after a while...a long while especially when inactive. If you kept the servos moving it wasn't as bad.


09-30-2008, 10:32 AM
I guess to be safe its better to use 6V. i wonder why at robotshop.ca they provide a 12V power supply with the PhidgetAdvancedServo Kit 4-Motor.... :|

09-30-2008, 10:45 AM
I'm planning to buy my supplies from robotshop.ca, that's why i'm looking at their website.

for soem reason, they only have 12V power supply with a wall adapter from Phidgets. this is a slight problem, because i'm planing to buy the Phidgetsadvanced 8 servo controller and attached about 7 servos to it - so i need a power supply.

i can buy the 'Switching Power Supply 6VDC 1.5Amp' from their website though,
could somebody please tell me if that will work and fit with the controller and servos i just described?

09-30-2008, 11:05 AM
Just confirmed, the Phidgets servo controllers do indeed have an onboard voltage regulator, so a 12v power supply should work. Believe the input rated on the 8 servo was 6-15v.

09-30-2008, 11:38 AM
Thanks Tyberius! so i guess i can just go ahead and get the 12V power supply.

09-30-2008, 01:30 PM
I have had students use 12 volts on a phidget 4 in a pinch. It got hot after a while...a long while especially when inactive. If you kept the servos moving it wasn't as bad.


I think it's largely going to depend how much current you're pulling through it. If it's a 6-15v regulator, 12v is up towards the end of what makes the regulator happy. If you're pulling higher current through the regulator, it may run cooler down around 9v with a higher current rated power supply.

Regulators don't like being run up near the end of their ratings for reasons I've documented ad-naseum here on the forum.

If it gets hot, check your current draw, then slap a [bigger] heatsink on the regulator. ;)

That said, if it's a 6-15v regulator (I don't have one to look at, so relying on what Tyberius wrote), I think I'd run mine on a 9v regulated power supply of adequate amperage.

09-30-2008, 02:05 PM
how can you determine how much amperage your robot will require?

09-30-2008, 02:12 PM
also: trossen or robotshop.ca doesnt seem to sell 9V Power supply, so as an alternative, could i use the 'Switching Power Supply 6VDC 1.5Amp' i mentioned before? would that work alright with the Phidgetsadvanced 8 servo controller, or would it not provide enough power? i'm also wondering if the 'switching' part of it will cause any troubles....

10-01-2008, 09:52 AM
Thanks for all the replies / discussion guys - I really appreciate you helping a noob out!

I see you have different opinions on the 12V power supply. As I understand - I guess the 12V might be possible, but using it comes with a risk. Since I’m a beginner, I’ll stay on the safe side and use a recommended 6V.

Would the 'Switching Power Supply 6VDC 1.5Amp' (http://www.robotshop.ca/home/product...dc-1-5amp.html) work alright with the Phidgetsadvanced 8 servo controller? provided also that I’m planning to attach the following servos:
Hitec HS-805BB Giant Scale Servo Motor
Hitec HS-755HB Giant Scale Servo Motor
Hitec HS-475HB Servo Motor
Hitec HS-422 Servo Motor
Hitec HSR-1425CR Continuous Rotation Servo

Thanks again for all your help and answering my questions :)

10-01-2008, 11:08 AM
No, in fact the board won't work unless you split the power off. The board isn't made to drive things like that 805BB servo.

REGULATED 12v is fine, btw, UNREGULATED is not... Please everything RM wrote, and then you can ignore my responses to him, and it all becomes simpler. I may just go back and delete all of that exchange to make it easier to follow...

But again, that's the wrong board choice for those larger servos.

10-01-2008, 11:16 AM
There... Much less confusing now. :)

10-01-2008, 11:30 AM
I understand. everything is now much less confusing indeed. but now that you're saying i cant use that controller, adrenalynn, could you please recomend a servo controller that CAN control the servos i mentioned (about 7 of them) - the easiest to use servo controller that a noob like me would most likely be able to use??? that would really help me alot.

10-01-2008, 12:15 PM
The SSC-32, the Pololu controllers (including the USB controller), ... Any controller that has separate power input for servos and logic. I don't see any included method of jumpering off the power on the Phidgets, and the documentation clearly states that you can't run servos larger than spec'd. (My 805BB can draw over 2A measured when stalled and warm)

You will need a MUCH larger 6v power supply - that's what powers the servos. I'd recommend something like 6v @ 5A.

The Phidgets could be modified to work. It would involve cutting/soldering traces on the board ["green wiring"], or you could split the servo leads separating out the power leads on the servos. I could advise on modifying the servos, but not on modifying the boards - I wouldn't give that kind of advice without a board in hand to modify.

Modifying the servos to work isn't all that tough - modifying a board would be.

I'm disappointed that the Phidgets controllers apparently insist that you use their onboard regulator.

10-02-2008, 10:39 AM
Ok, i looked at the SSC-32 and it documentation. Along with your recomendation and your tutorial of how to control it from C# makes it my new choice of controller - it should be able to control the servos i mentioned, as you say, and it has a seperate power input for its servos.

could you please suggest, adrenalynn, a power supply to power such a system of servos and controller?

Hitec HS-805BB Giant Scale Servo Motor
Hitec HS-755HB Giant Scale Servo Motor
Hitec HS-475HB Servo Motor
Hitec HS-422 Servo Motor x2
Hitec HSR-1425CR Continuous Rotation Servo x2
SSC-32 controller

10-02-2008, 12:48 PM
My arm is using an 805BB, 3x 645MG, 2x475HB. I further have 2xFPS148 on the project right now.

I don't have experience with the continuous rotation servos mated to the SSC-32, you may want to do a web search or someone else can chime in on that.

One thing to note: Make sure you have a serial port on the computer, or a working Serial->USB adapter!

I don't know much about your project, but one thing to consider is how many servos will be at continuous operation simultaneously. My project runs part time from battery but on the bench it runs from an adjustable voltage power supply I picked up at the local Fry's Electronics. It's an HQ Power PSSMV7U. It generates anything from 5v-24vDC using little plastic inserts (probably with a resistor built in to control the regulator). At 5v it makes 4A, at 6v it makes 3.5A, and continues on down. I paid about $25 for it, and it doesn't even get warm driving the eight servos I listed.

Doing a web search with the part number I listed, I see probably a hundred or more sites selling it. It appears to be made by "Velleman".

Looks like I got a heck of a deal on it, wish I'd bought all of them - everyone seems to be selling it around $50.

10-02-2008, 02:18 PM
that seems like a really good power supply. what configuration do you use on it? 6V 3.5A?
i'll check my local store and try to get my hands on something similar, it seems like a good choice.

i am not sure if i have a serial port connections (not at home right now to check) do you think a "Cables Unlimited USB 2.0 to DB9M Serial Adapter" 3would do the job fairly well? (http://www.tigerdirect.ca/applications/SearchTools/item-details.asp?EdpNo=1104139&CatId=77)

when you say your project (which seems to have similar power requirements to mine) runs part time from battery, what kind of battery do you use then? and what V and A does it have?

10-02-2008, 09:52 PM
I use 6v @ 3.5A.

I wouldn't recommend a USB to Serial because they're too darned finicky. It's one of those "find one that works and run with it... " Almost all of them have the same chipsets but they all work/not work differently it seems - so anything I recommend may suck on rocks or be great - or both. ;)

I'm using a Castle BEC (Thanks, 4Mem!) with a 9.6v NiMH @ 4800mAH battery now.

10-03-2008, 09:32 AM
Alright, well, due to the lack of other options, if i dont have a serial port, i will have to try and work with the USB to serial - there seems to still be a chance the cable will work as you say.

how did a 9.6v NiMH @ 4800mAH battery work for you? the servos you mentioned earlier have a max of 6V on them??? or is there something i dont know / forgot to take into account?

10-03-2008, 11:11 AM
how did a 9.6v NiMH @ 4800mAH battery work for you? the servos you mentioned earlier have a max of 6V on them??? or is there something i dont know / forgot to take into account?

I'm using a Castle BEC

BEC = Battery Eliminator Circuit - it's like a big voltage regulator.


10-03-2008, 04:03 PM
Ohhh ok. you see, i dont know much about the voltage regulators or any of those acronyms. trying to learn though.

I am confused a bit now - i am trying to figure out what power supply i should get for the ssc32 controller and my list of servos that i'm going to get for my project. there will be about 7 of them, but i dont necesarily need more than 3 to move all at once. i apologize for all the noob questions i'm throwing around here, but as soon as i figure what i need to get i will get it and start the more quite 'building' job!

so which battery pack would you recomend?

i was also thinking of building a battery pack/holder myself. putting 6 energizer rechargables in a Series configuration to get around 6V @ 2000+ amps. then to make another one and put it in parallel configuration to the first one, getting 6V @ 4000+ amps. would that work or am i just crazy? (i just read up about parallel and series and thought i could put it to use by making this idea; considering you sugested i would need over 4000 amps for all my servos)

10-03-2008, 05:39 PM
First - it's "millamps" - 1/1000th of an amp. 4000 amps would need cables the size around of your leg. ;) I know you know what you meant, just underscoring it.

You don't want "around" 6v. Servos are touchy critters. 6x1.2v = 7.2v = dead servos (unless they're 7.2v servos like the 599x line). That's why you use a regulator like the BEC I mentioned above. You can set it to be EXACTLY 6v, or EXACTLY 5.8v and leave some safety margins.

The servos may not all be moving at once, but they're probably all "holding" - which can be even worse than moving. Basically they're correcting themselves like 25x a second under the full load of what they're holding. Holding is what pushes servos closest to stall in my experience - so any good design should plan on full current plus some safety margin.

Another advantage to the larger battery I'm using on the BEC is the equivalent power - Watt's Law, Ohm's Law, etc. You lose some in waste heat, but you still have more potential power in a higher voltage battery being stepped down through an adequately sized regulator.

It will also take longer to get a 9.6v battery discharged to <6v than it'd take a 7.2v battery to discharge down to <6v - that's where the calculations in the paragraph above come into play.

There - are you confused enough now? I use a 9.6v 4.8Ah (4800mAh) NiMH battery (Specifically the Tenergy brand performance R/C battery) discharged through an adjustable regulator (BEC) set for 5.84v under load...

10-06-2008, 02:58 PM
[originally posted by bodhibuilder]:

Thanks for noticing and correcting my mistakes and misspells :) without that i would probably have blown up a few servos by now!

i looked up your Tenergy battery and it seems pretty good - thinking of getting one myself.

the castle BEC you are using is also a very usefull piece it seems, but to buy it and the usb cable needed to reprogram its output voltage adds up to be pretty expensive (more than the actual battery pack!). i am looking for a cheaper solution. for example, is there a cheaper BEC that might not have its output regulated, but is set to 6V?
(i am looking for a way that's as-cheap-as-possible to provide DC energy for my robot arm)

10-06-2008, 03:00 PM
Unfortunately, that's a contradiction in terms. If you can take [insert random voltage here] and spit-out a constant 6v - then it's regulated.

10-06-2008, 03:01 PM
Sorry - I responded to Alex's paste of your original question. You might contact Castle and ask 'em to program the BEC for you at 6v. Or just run your servos at 5v...

10-06-2008, 03:03 PM
oops, i didnt mean to say its 'not regulated', i meant to say that the the output voltage isnt adjustable and just set at 6V (regulated). i'll try to get my terms straight-er in my next posts.

10-06-2008, 04:01 PM
Alright, so after reading, learning and researching a bit more, i have a few more interesting questions / comments:

1. inputting 7.2V or 9.6V outputting 6V should create heat and energy wastage from the conversion with a linear BEC (the Castle one is linear, no?) so wouldnt that be a less than optimal way to regulate output V?

2. would i still need a BEC or anything else like that if i got a regular 6V battery pack such as this one: http://www.all-battery.com/nicd6v5000mahbatterypackforemergencelight.aspx
or can i assume i can connect this 6V battery pack straight to the SSC 32 and have everything be alright and working?

10-06-2008, 04:55 PM

Any conversion has loss. Loss = heat.

You could use a NiCd. For a while. Short while.

The 1980's called, and they want their NiCd's (and this joke) back.

Super-long charge times (for a 5kmAh plan on at least 25hrs between uses), and super-short life (memory).

We've kinda moved on since then... ;)

10-07-2008, 08:22 AM
Hahaha. Actually, TANSTAAFL apperantly did not apply to me yesterday as we had a company lunch (free, naturally).

I agree that any conversion has a loss, but as i understand - if one was to use a switching power regulator / converter, it would put less energy to waste than the linear castle BEC, for example.

what i was wondering about the NiCd battery i linked to in my previous post is; if i can take it (its 6V) and directly connect it to the SSC 32 and to the servos. my understanding is that since the servos are can handle up to 6V and the battery itself is 6V, that should be possible without blowing anything up, right?

(and i always thought that battery technology is like wine - the older the better... :P )

http://www.all-battery.com/6v3800mahnimhhumpbatteryreceiverpackswithtamiyaand jrconnectorcustomize.aspx (NiMh, a better choice for Y2k+?)

10-07-2008, 08:38 AM
what i was wondering about the NiCd battery i linked to in my previous post is; if i can take it (its 6V) and directly connect it to the SSC 32 and to the servos. my understanding is that since the servos are can handle up to 6V and the battery itself is 6V, that should be possible without blowing anything up, right?

6V is the nominal voltage - 1.2V per cell x 5 cells = 6V. Unfortunately, when freshly charged the actual voltage will probably be between 6.6 and 7.2V. It will then discharge down until it hits around 5V before it stops giving you much current.


10-07-2008, 01:26 PM
I see, so i guess i will have to use some sort of a regulator after all. now if i could only find one with an output of 6V and 4A or more...

10-07-2008, 01:36 PM
Whiiich is what the BEC is. A regulator. That outputs 6v @ 4A or more. :)

10-09-2008, 09:12 AM
Ok, i guess i'll go with the Catle BEC. its not optimal in some ways but i guess its the best option i have. Thanks for all of your help guys! i think i finally understand what i need to get to start building my robot. :)

10-09-2008, 10:54 AM
If there's a more optimal way to battery power those servos safely, I definitely want to hear about it!

10-09-2008, 02:11 PM
I'm not sure, i'm new to this, but i read a switching power regulator would be more efficient/optimal. i found some sold on some website, but there was no picture and no one seems to be talking about them so i'll just go with the linear castle BEC. plus you, Adrenalynn, know your stuff so if you say its good; its good.

Now, i dont want to ask repetitive/noob questions, but i noticed on the ssc32 board's manual it says the following about the power input terminal: (http://www.lynxmotion.com/images/html/build136.htm#aglance):

"This terminal connects power to servo channels 16 through 31. Apply 4.8vdc to 6.0vdc for most analog or digital servos. This can be directly from a 5-cell NiMH battery pack. 7.2vdc - 7.4vdc can be applied to HSR-5980 or HSR-5990 servos. This can be directly from a 6-cell NiMH battery pack or a 2-cell LiPo battery pack."

does this mean that i really dont need a BEC and can actually just connect directly to the SSC32 a 6V battery (such as http://www.all-battery.com/6v3800mahnimhhumpbatteryreceiverpackswithtamiyaand jrconnectorcustomize.aspx) and everything will work ok without blowing up?

10-15-2008, 03:00 PM
Ok, so i'm in the last stages (i hope) of deciding and planning what to buy to start my project. i am posting a picture and specifications of the hardware i'm planning to get. does this look right? am i missing something? input is really really really apreciated at this point (wouldnt want to miss anything or waste money on something i dont need)

List of items:

Hitec HS-475HB Servo Motor
Hitec HS-422 Servo Motor x2
Hitec HS-805BB Giant Scale Servo Motor
Hitec HS-755HB Giant Scale Servo Motor
Hitec HSR-1425CR Continuous Rotation Servo x2

Lynxmotion SC-01 Servo Single End Cable - 12" x7
Lynxmotion Quick Connect Battery Connector

Servo controller:
Lynxmotion SSC-32 Servo Controller

battery packs 7.2V 4200mAh

Voltage regulator:
Castle BEC

10-15-2008, 03:02 PM
Are you going to run them at 5v, or are you going to need to pick-up a programmer too?

10-15-2008, 03:06 PM
i'll stick to 5V for now. i'll get the programmer when the economy picks up :P

10-16-2008, 08:47 AM
Besides the 5V, does everything else look like it could work? (nothing missing, everything is connected correctly, etc)

10-16-2008, 12:10 PM
Actually, no. The way you have it connected will smoke the regulator on the SSC32.

You need to separate VL from VS1/VS2. The BEC goes to VS1/VS2. You could "Y" off from your battery and run that into VL as long as your battery is going to be >6v for the life of the application. Or you could just use a 9v "transistor radio" battery - or "smoke detector" battery as we call 'em today - on the VL.

VL is Voltage/Logic power to the processor, and VS1/VS2 are voltage to the servo banks.

You'll need to remove the VL=VS jumper and jumper the two VS1=VS2 jumpers.

10-16-2008, 12:25 PM
You know - I might hold off a bit longer if you can. I've found some other BEC sources that don't require a programmer and appear at first blush equal or greater power at similar pricing to the Castle minus the programmer.

10-16-2008, 01:49 PM
Thanks! thats an excelent tip - saving me from blowing things up once again. i really apreciate the time you take to answer my questions, adrenalynn - i will name a part of my robot after you! (the brain?) :P
in general, this is an excelent forum, i find, where people come together to teach and learn from each other. hopefully one day i'll be on the teaching side..

anyway - a better or a more appropriate BEC would be great! when will you have some information or a link to it??

10-16-2008, 02:33 PM
Thanks for the vote of confidence!

Give me a day or so to investigate the different switching ubecs out there. There's some great looking ones for LiPo R/C planes that look promising. I don't see any reason they won't step-down NiMH or lead acid in the same voltage range, but the one I'm most interested in has a charge indicator that may not like the "non-funky" non-LiPo voltages. I have an email out to the manufacturer to see what they think. If it works, we're looking at ~$19 switchable from 5 to 6v with an onboard switch. As long as you don't envision needing it to provide some other voltage function, a programmable BEC may not be as cost effective as a switchable...

10-16-2008, 03:04 PM
This kind of regulator would be really good. i'll be waiting for an update on your findings :)

10-20-2008, 08:39 AM
hey adrenalynn, do you have any news about those ubecs you were investigating/recommending?