Let's Make Robots!

LineB


I started on a new robot. Totally thought up from my head. I thought of a line following robot that should be pretty easy. LineB or Line Bot. It uses kinda a lot of transistors and a compartor chip. LM393. I'm sure this should work.

So the robot runs of a 5V power supply so I built a 5V regulator circut.

P2090161_0.jpg

The zener diode is always on. When the battery falls below 5.6V the diode turns off and so does the LED. Telling you the battery is out of juice.

 

Sensor Circut/Inverter

 The senso I bought coul only sense White lines on a black surface. The real problem was if there was not black surface or if there was no white line. So I had to come up with an inverter circut. Consisting of a bounch of transistors. the extra one on the far left is for replaceing the sensor becouse I haven't got it in the mail. :p

P2090162.jpg

NonInverting

The Sensor is on. The Led is on.

P2090163_0.jpg

 Sensor is off. Led is off. Simple!

P2090162_0.jpg

Now comes the hard part.

Inverting

This took me lots of thinking time until I thought that a capacitor could do the job of overiding the PNP transistor to turn off when the sensor is turned on.

The sensor is off. The Led is on.

P2090165.jpg

Senor is on. Led is off.

P2090164.jpg

 

The LED's will be replaced and turned into inputs to the LM393. There will be a second circut like this for the left side. The output of the LM393 will power  a transistor that will power a motor. :D

 


Here's the schametic of the circut above.

 

Liney_circut.jpg

 

 


2/12/09

 

 

I started on a PCb because I really prefer the neat PCBs than the ugly point to point sodering. It's only half way done. The power supply indicators and chip are put in. just not the sensors and motor drivers.

Line_B_unfinished.jpg

 

 

 

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I'm working on something like this too for a line follower. I'm also using the LM393 to compare the inputs from CdS cells. My idea isn't original though, I got it from David Cook...haha
It's good to see someone experimenting with transistors and simple electronics. I would like to see your schematic since some of your explanation doesn't make sense to me. I'm not certain why you have so many transistors or how you are using that capacitor.
sure i'll upload a schemetic. but it's incomplete because I haven't added the motor circut yet. the transistor the controls the inverion light in usually conected to ground. but when the transistor in front of it turns on it overides the pull down resistor connecting the capacitor to power and keeping the transistor off.
It always amazes me how anyone can build anything without a microcontroller!
Pretty cool work, hope to see a diagram of the circuit. Think you mean LM339 quad comparator. Good chip.
nope it's the LM393 dual comparator