Ezb V4 Power Shield , 5 Volt, 6v, 7.4v , What Do You Want?

 
#1

Hello Everyone , I had this idea when the v3 was around , but I wanted to wait until v4 was in circulation before pursuing it. The concept is a shield that plugs in directly on top of the existing EZB v4. It would regulate 5 volts on the power pins. Then of course I was thinking... WAIT! 5 volts is a fine standard, but servos run on 6 volts by standard and some high torque get the most power with 7.4 volts! So there are some options. I want to make this shield generally available to the community for testers. I imagine two or maybe three different versions of the shield would be appropriate.

1. 5 volt Standard Servo shield- all 24 digital power pins regulated by a switching psu , green certified , Gold standard efficiency 96%

2. 5 volt @7.5amp with switch to 6 volt @ 10amp Boost for High Torque servos, preset for all 24 digital power pins , switching psu, green certified, Gold standard efficiency 96%

3. Dynamixel shield option - 5v @5a and secondary power option 12v @10a continous.

The switching regulators cost more however they produce less heat and waste less power. This increases battery life of your project.

what I would like is feedback on is how I should lay this out. How do YOU as a user want the shield.

1 Top mount pins line on v4 now or 90 degree out to the sides?

2 dip switches or physical jumpers to change voltage from 5 volt to 6 volts (or 7.4 if your servos can take this continuously )

3 what battery voltages does everyone use, I want to configure shield for most users so they do not need to use a plether of step down converters.

4 whats your idea or opinion , lets be constructive afterall I am doing this for you Smile

#2

5V for sensors. 7.4V for servos. Banks of 6 ports with variable voltages (all three you suggest, but with 7.4v being "pass through"Winky would be how I would plan it.

Having said that though, the EZ-B V4 layout it very user friendly, is there a need for a shield? Possibly smaller voltage regulator shields split to the 6 port groups or for each side of the EZ-B but I see little to no advantage in re-routing the entire EZ-B V4's ports through a shield when practically everything is plug and play. I'm not saying don't do it I'm just questioning the reasons why you see a need for this (and others seeing a need for it).

#3

Maybe not entire shield, but how about small header pin assembly to only cover say one of the 4 pin rows on the ezb for 5v sensors?

#4

I am with @Richard R.

I don't personally have a need to regulate all of the pins, but it would be nice to be able to select a subset of them for 5v (and maybe 5v signal as well since some devices appear to need that, like some of the relay control boards). That being said, I think there is a need that you would be meeting either way you choose to do it. I think if you make a shield, then having multiple voltages available on the same shield would be good, either individually or by groups of pins. Personally prefer dip switches to jumpers, but jumpers probably give you a lower cost of goods.

As for input power, I plan on using either 12v or 24v SLA. (depends on which motors I wind up using). I planned on putting a regulator before the EZ-B to knock it down to 7.4v, but I wouldn't mind going with 12v input and using a regulator shield on the EZ-B.

Alan

#5

@Alan... A level converter... good idea....

#6

I use 12volt sla batteries and I would love to see a top mounted shield so that i can connect servos and sensors without having to use a dc regulator external. Currently have to breakout the three standard pins for servos. Withe a shield i would not have to do that. I think a shield with 5volt for sensors and 6 or 7.4 volt selectable for servos..The shield would also stop me from plugging in servos to ezb pass thru voltage by accident or sensors!

#7

@RB550, Yes that's true ! It would prevent the accidental damage of sensors when you plug them in and realize.... oops , " I just let the magic smoke out of that 30 dollar maxbotics sensor I just bought!" It's really an inevitable mistake.

@Alan , I am reading over data sheets till my eyeballs hurt to find switches that small that can also handle 1 amp + current to run through them. The dip switches I have seen so far are 25ma to 200 ma which is fine for a LED light but not a servo. So either a larger switch or jumpers may be the answer.

#8

But would it prevent accidental damage? If the shield is set for 6v or 7.2v and a 5v sensor is plugged in it would still smoke.

The switch may not need to handle the full load current. Transistors may be able to be used to allow a small switch be able to enable a large load. Think about the principals used in the TIP120/TIP122 circuits.

#9

@Rich , If the shield came preset to 5 volts then yes it would prevent the damage , someone would have to change it then plug in the sensor to the 6 volt output. All scenarios to prevent damage cannot be prevented, but as a experiment I let 5 people try to set up a basic radar test and motion detector. This is after after watching some tutorial videos to show how easy it is and all forgot that the voltage would damage the ultrasonic and motion detector modules we were using. I recorded it but didn't post because... well that was embarrassing lol. I bought a pack of ten sr04 , so I was prepared for a magic smoke party. Lol

#10

I pointed out I could make a ALL 5 volt shield and then a alternate shield for the ezb pros , with servo boost voltage. The 5 volt may really be best for the beginners to ez robot or electronics in general.