Nighthawk355
Hello all,
May i introduce myself, i am Garrett and am constructing a robot for a class project. I have run into an issue in charging my robot and have not yet been able to locate an answer in this forum and online.
My issue is:
I am going to run two motors with TB6612FNG dual motor controller. To my understanding, i cannot run the power source for these two motors directly off of the EZ-Board... I must supply a seperate power source to the motor connecting it directly to the HBridge and a seperate power source connected to the EZ-Board.
I want to create a docking station that the robot can connect to and charge both the battery for the motors and the EZ-Board without turning the robot off. I cannot seem to find a splitter or the right information to complete this task.
Any ideas?
Thanks,
-Garrett
here is idea for a backup battery ,close to the kind used in laptops two 3 volt coin cell battery in series like CR2302,i am using that for my robot projects
@robotmaker
The battery backup system is great. However my other challenge is how can i charge my 7.2volt battery and continue to have power to the robot for me to take it off teh charging station once it is finished? Below is a picture of an idea that our group had... it does not utilize the battery backup system.
problem with that is, charges work like this they charge your battery by current and if you have another load like EZB board hook up to it wont charge correctly thats why always good to remove or use a disconnect switch or relay to the battery and have a backup battery that keeps the unit on
it may work like that only if EZB and all sensors attached and you measure current to be under 10 ma
wow i just measure the current of EZB without sensors almost 100MA so you really need the backup circuit
Okay, so i definately need to incorperate the battery back up system below
However, where in this does the relay come into play? In the drawing i show the connection / disconnection point in which the robot will interface with the charger.
Oops, i guess some sort of pressure switch at connection point "S2" would work wouldn't it? Something that the robot could drive up onto the station, then compress the switch to then disconnect the main power source from the robot. Once this happens the robot motors won't be active though... which is a problem to get the robot to move backward uncompressing the switch to allow the main battery to be utilized.
any ideas?
-Garrett
relay instead of switch 2,can use a switch or relay or relay is good becase you can drive it from EZB digital output board ,like a reed relay you do need a transitor to turn on the relay plus added idea is to monitor the battery when battery fully charged the relay disconnects then you have a automatic charging station
Ok so a relay at switch two would work. However how can power still get to the motors? The relay would be cutting power to VM positive line which I thought powers the motors?
dont need power at the motors till ready to move after charge,when charge is done battery connects to motors and board
on batteries not all coin cell batteries are rechargeable,found out that cr123 batteries are,and cheap on ebay,need 2 of them,but and small 6 battery will work only need about 300 ma