Let's Make Robots!

BubbleBoy v1

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Dan M's picture

I like this little fellow a lot. Gold star for imagination and a smiley-face for cuteness.

(Oh, I don't see the LCD in the schematic, but presume it ties to other arduino leads.)

psychofreaky's picture

I like the concept of this robot. But I object to most fluffy pink things. -lol

 

lazybum95's picture

i dont meen to be mean but i think i seen this on tv or something. they made something like this to teach children to make direct eye contact. what i meen is it had sencers in its face if it dosnt detect that anyone is looking at it it will dance and move around. it was made to teach childer to keep eye contact when there parents were talking to them or something like that. but im just saying it looks like what i seen it dosnt meen yours does they same as it.

but it does look cool the one i seen was jsut plain and yellow (i think it was yellow) but you added things that ar eye catching.

CaptainTuna's picture
Other members have already appreciated the originality (does that word exist) of your robot :) so i'll ask you a techy question (i'm quite noob actually). What is the diode that connects the emitter to the collector for?
RobotGrrl's picture
Thanks! I'm quite noob too. It's a Snubber diode :)
robologist's picture
That's what jka was saying up there, the snubber / protection / flyback diode is not doing what it's intended for, since it isn't connected across the load. It only functions to supress the transient high voltages if it can form a circuit around the inducutive load (the motor) to drain off the excess voltage generated when the transistor is shut off.  For protection, the diode should be connected with the cathode towards the positive voltage side of the motor, and the anode towards the ground, transistor side of the motor. (Basically the same as you have it, except across the motor rather than the transistor).
jka's picture

Exactly. Sorry for not clarifying in my original post. When you stop the motor and the magnetic field collapses, it can/will generate a high voltage spark that can destroy the transistor. To prevent this, you mount a clamping diode as robologist described.

This applies everywhere you use a coil. That is, for example, motors, solenoids and relays

Dan M's picture

No, actually, while many people put it directly across an inductive load, the reverse voltage transients will bypass the transistor, protecting it. The diode provides a low resistance path to ground/supply compared to the higher reverse breakover needed for the transistor, so it will work fine as she has it for transistor protection.

The only drawback is that putting it across the transistor can still allow a power supply spike, which could affect the other components, but if the power is from batteries, they will have a great dampening effect on an spikes hitting the supply, so no problem overall.

(Hope that clarifies things.)

 

 

 

jka's picture
If it's a protection diode, it is misplaced. It should be across the motor pins and not the transistor.
maneuver's picture

Great idea, great color. Just out of curiosity, is this part of the EPGY study? 

I like the effort you've put into trying to show emotions without trying to copy human behavior. Is this a finished project? Is it the first in a series? When does the blue version arrive? 

/ vzz-clck-"Maneuver"