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Asked — Edited
Resolved Resolved by Rich!

Question On Wirings Of The Modified Omnibot2000.

Ok, here is what I finally came up with. Please give me feedback:

I start off with 12vdc which goes to the switch and base. From there it goes to a BUCK 15A Regulator which steps it down to 7.2V and it goes to EVERYTHING else. Two EZBs get their power from this. The two arms get their power. So, I will be operating two EZBS and 17 Heavy Duty servos from this 15A regulator. I have 43 more 2A regulators if I need them. But, I hate to wire all of those. I am running out of room to put all of this.

Oh, by the way, I get the power from three 9AH 12vdc PowerSonic Gel Cels. Oh,and MONEY has become an issue.

Suggestions Welcome.

Thanks,

;)


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United Kingdom
#1  
Are they EZ-B V3s or EZ-B V4s?

I ask because if they are V3s there is no need to regulate the supply therefore allowing more current for the servos.

15A to power 17 heavy duty servos which can pull as much as 2A on full load (depending on the servo used) may be a little undersized. Personally I allow 5A for every 2 servos, this way I know it wont be too demanding for the regulator (as previously stated elsewhere, 2 x Tower Pro MG995s and 1 x LCD display were causing my EZ-B to brown out therefore were pulling over 5A combined).

Personally speaking I would supply the EZ-Bs with 12V. Regulate the VCC from the EZ-B to 7.2v (if V4) with the individual 2A regulators.
#2  
I have two EZB ver. 3. But, one is broken. I have a ver. 4 on order. So, she will wind up with one of each.
United Kingdom
#3  
Well the V3 will only provide 5V to servos regardless of input voltage so those 20 ports will be limited, unless you tap off of the regulator before the EZ-B. Either way, powering this EZ-B from a regulator would be pointless, you may as well power it direct from the batteries.

You could also power the V4 from the batteries. Connect the regulator to the batteries and take all VCC and Ground from the regulator rather than the EZ-B... in other words only the signal from the EZ-B is used.

Although I am concerned that the 15A regulator is not going to be man enough to power everything.
#4  
Now, if I power it from the Battery, it will be getting 12vdc. I stepped it down because it was said that 7.2vdc was the IDEAL voltage. I am concerned also about the regulator. But, if I go to a 20A, it only gives me 5volts to work with. I need 7v for the arms to work strong. I can't find a 7v out 20A regulator with 12v in. I have to also power two pitman motors and a second H-Bridge from this regulator. Or, maybe I can get it from before the regulator. I am very confused.

Thanks for your help. We will see what other people think.

*confused*
United Kingdom
#5  
When I get chance I'll draw up a quick schematic of how I would do it which should hopefully be clear enough.

The V3 works fine on 12v. My test rig runs on 12v and the on-board regulators barely get warm.
#7  
The problem is, if I use the little 2A ones and I am going from a single source, the source will be combined amps. And , if it goes over 2A I will be in trouble.

Unless you are saying tie directly to the little ones from 12v Battery?

In that case, I run out of room to put all the wires and such. But, we will see.

Maybe I can put the regulators inside the arms.
#8  
Thank You all for the answers you gave. You all deserve credit. But, there can be only one, so Rich was the first one to give an answer. Anyone else is welcome to make suggestions. . .I like input.

:D
United Kingdom
#9  
A quick schematic I did earlier when I had 5 minutes, apologies for it being so crude but hopefully it helps explain things a little.
User-inserted image


This way the EZ-Bs aren't eating in to the regulated supply, leaving the full 15A for servos and motors. It also means that you could put sensors etc. from the V3 without any regulator needed and 5v servos without any regulator needed, this would also not be taken from the 7v2 15A regulator leaving more power for those power hungry hd servos.

The V4 would output the full 12v on the VCC pins but these could then be regulated down with the smaller 7v2 2A regulators you mentioned, again not eating in to the 15A regulated supply but still providing 7v2 to the servos where needed.

I also added on a note after I drew it up about the H-Bridge. It may be possible to take it's supply direct from the batteries rather than using the 7v2 regulated supply (check the motors). The DC motors will no doubt demand high current so it would be best to avoid supplying them from the regulator if possible, or if they do need 7v2 then possibly add in another regulator for the motors.

Hopefully that all makes sense.
#10  
Hey, Rich! I am doing some honeydos right now and don't have time to look at this very much. But, I want to thank you and I will look at this as soon as I get the claws out of me. I really, really,really appreciate what you have done,my friend.
:D:D:D
#11  
Ok, you are saying run the EZBs directly off of the 12v batteries.
Then run the sensors off of the EZB Ver.3.
Then run all servos off of the 7.2V Regulated 15A supply.
Install 5v regulators on the sensors that go to the Ver.4 , if any.

I have two H-Bridges. One for the Base and one for the shoulders.
So, run the base off of 12vdc to give it more power.
Put the shoulders on a 12v battery source.

I have 14 heavy duty servos in the arms.
I have 2 pitman motors in the shoulders
I have 1 sonar scan servo HeavyDuty.

So, that is 16 servos and I have only ONE 15A Buck Regulator.

Is this what you said? I think I understand.
United Kingdom
#12  
Pretty much yes. Anything that works fine on 5v for your build run off of the V3, this will save any regulators being needed. Also bear in mind the V4s Analogue is regulated to 3.3v so analogue sensors also wouldn't need additional regulators.

Although I wouldn't put the shoulder motors on the 7.2v regulated unless they have to have 7.2v. If they can accept 12v I would come direct from the battery. Check the motor and H-Bridge ratings though.
#13  
Right, I am going to change the shoulders to run off the 12vdc. I will edit the post above.

Rich, I wanted to say something. I have been retired for a while. But, when I was working, I had a job that I was a supervisor/manager. I was in charge of one young man called: Hugo Rapsen. He came over from the UK the day before. and he was such a nice, dedicated young man. He was quick and he was correct in most all of his calculations. I just thought a lot of him. Anyway, you remind me of him because you have all of those same characteristics. Also, he was a Linux man. He breathed Linux. He was sold on Linux. Our company had not gone over to linux yet. I personally was operating UBUNTU at the time.

With that being said, I will stop jabbering.

;)
United Kingdom
#14  
Thanks for the compliment. As I've said before, it's the whole "teach a man to fish" philosophy and wanting to see what can be achieved (the more who have the knowledge and tools available to them the better the chances are that we will see a world changing robot soon).

Besides, it is a welcomed escape. Believe it or not I also work an 8.5 hour day 8am-4:30pm, come home and work again for 7 hours from 5pm until around midnight (hence very little progress on Melvin lately). These little breaks are what keep me sane I guess:)
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