HI, I'am working on making a robot called the "Herbie Photovore".
I'am following a book called "junk bots bug bots and bot on wheels":

[/SIZE]"]http://books.google.com.au/books?id=vY2hd3bCQw8C&pg=PA131&lpg=PA131&dq=herbie+photovore&source=bl&ots=-19P7LZQ41&sig=T8ylA4q0AvqrGQL3nRVfP8D215w&hl=en&ei=LQcCTZ7vH4rirAemxIiRDw&sa=X&oi=book_result&ct=result&resnum=7&ved=0CEcQ6AEwBg#v=onepage&q=herbie%20photovore&f=false

Pgs 131 to 164

The problem is that the touch switch on the end of the robot that is supposed to reverse the robot for a set amount of time isn't doing anything And I'am just wondering whether it is because I'am using a 2N2222A transistor in place of the PN2222. I have spent many hours and replaced the capacitor, resistor and transistor for new ones already so any help would be very much appreciated.

Thanks
Calem Young

 

The two transistors are the same, just different manf.

A schematic of the circuit in question would be required, or the answers will not help much.

 

ok I have uploaded the schematic.

 

ok I have uploaded the schematic.

It's too small to make much sense out of. What is the cylindrical object that is activated by the backup switch?

 

Yeah it is a bit hard to understand..
The cylindrical object is a 100uf capacitor which along with the resistor, times how long the transistor activates the relay for reverse behavior. and all of that is suppose to happen when the backup switch is activated.