dalex
Belgium
Asked
— Edited
I managed to destroy one Robosapien board by putting 6v where it shouldn't go
I'm going to use the 3.3v supply on the ez-b to power my other Robosapien, but now I'm a bit nervous about blowing it.
What resistor should I use to drop the voltage from 3.3v to 3.0v? I read up on Ohm's law, but it seems to depend on how many amps are being pulled. Is that right?
I need to run two cables from the 3.3v supply on the ez-b to the two 3.0v inputs on the Robosapien board.
Any thoughts?
p.s. electronics novice, don't underestimate how little I know
Why not use the 6 volts on robosapien board,they use the 2 3 volt batteries to get 6 volts to control the robosapien.
IF you look at the tutorial that DJ did on cennecting the EZB to the robosapien i shows to connect to the 6 volts not 3 volts.
I have the DJ version up and running already, drawing 6v from the Robosapien switch to power the EZ-b.
But the Robosapien board does not use 6v, it uses less. It blows up if you try to put 6v into it, I tried.
I'm going to run the Robosapien and the EZ-b from the same power supply, which is some 6v rechargeable batteries. So the simplest way to do it all (I think) is to drop the EZ-b's 3.3v output down to 3.0v, and feed that into the Robosapien board where the two 3v inputs connect.
Found the answer here I think:
http://en.wikipedia.org/wiki/Voltage_divider#Resistive_divider
Just need two resistors.
Yes, a voltage divider resistor set up will work, a simple calculation to work out resistor values... if it needs 3v from 6v then 2 of the same value will do it (see my LiPo balance Port Charger tutorial for a 1/2 voltage divider if you need another example, it's in Hardware somewhere
)
Hey Rich, Do you lose battery charge by running some of the power through the R2? If yes, what' the most efficient way to drop the power, in terms of battery life? David.
Only PROBLEM with resistor you will find is that you need a big wattage type ,because of the current draw of robosapien plus if using everything else it draws a lot of current, about 2 to 3 amps or more
There is high current motors on the feet plus other motors used in the arms and hands ,plus cpu on the main board and sensors.
PLUS second part you will see is that the main pcb on the robosapien needs 6 volts
Can find the link on the teardown of the robosapien models is shows it needs 6 volts on main board for it to work.
PLUS not very stable,i am electronic engineer
Voltage divider is great for analog circuits,becuase it only uses very low current.
Hmmm, maybe I should just put a 6v rechargeable in each foot, along with one of these to drop it to 3v:
http://www.ebay.co.uk/itm/LM2596-DC-DC-Step-Down-CC-CV-Adjustable-Power-Supply-Module-Output-DC-1-5V-35V-/300882588078?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item460dfff1ae
They're rated to 2A each, without an additional heatsink.
WITH 6 volt battery dont need to drop it to 3 volts,may be you dont understand about robosapiens to much ,i have many of them and repair them they use two 3 volt batteries in series if you trace the wires you will see negative going to positive to get 6 volts total
What you will get is 12 volts to robosapien board and robot and it will smoke it,now there is a easy fix that will work i did it on mine tie the 2 red wire together and the 2 black wires together to get 6 volts at double the current.
IF its hard i can try to explain it better.