Let's Make Robots!

any schematic design for brainless/no PIC/no microcontroller. avoiding obstacle robot??

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yeah i change my motors.. 


im using two supplies 9v.. 1 for the sensors and 1 for the C, NC, NO in relays..  


im using this logic Simple%20Bot.png 

joC's picture

Well, now I'm completely lost.

If you're using the IR receivers to trigger a couple of SPDT relays, where does the h-bridge fit in?


thanks dude..

i would like to try dis dy9wUCxwzK19.gif

i will just put this h-bridge in relay hbridge.gif

hmm. but i want to reproduce it twice.. should i use dual timer? or just simply reproduce the RECEIVER and relay? 

joC's picture

'ullo, you're back!  Couple of points:

The h-bridge is not a drop-in replacement for the relay.

Regarding the h-bridge you've shown, you won't be able to drive the upper NPN transistors into saturation unless the h-bridge voltage is a couple of volts lower than the control voltage.

Saturation in h-bridge transistors is A Good Thing.

If you are still going to use a single supply for both control and motors, I can suggest other h-bridge configurations you can use. Also if you want to drive the motors from a higher voltage than the control voltage.

If you keep the 74HC14, you can use a couple of its inverters to drive the h-bridge, and use another inverter to make your oscillator, obviating (that's a good word, isn't it!) the need for the 555 chip.

P.S. Did you end up swapping out those high current motors?

TeleFox's picture
Just use one 555 and duplicate the receiver circuit.
haha. sumthing went wrong while im testing it again.. sumthing smoked.. but i think it's shorted.. may be i connect some wires.. hah.. this weekend im gonna buy new components and ill directly put it in PCB.. maybe ill use presensythised PCB.. wish me luck.. thanks for your help joC.. you help us a lot..
joC's picture
No worries, aidzmana. I hope it all works out.
hey can i series two IR led right?? and minimize the R1 to adjust the range. up to?
joC's picture
Yes, that would be ok. R1 at around 150 ohms or so for an IR LED current of around 25mA.