hi all,

these circuits work. but i found a problem, when the tx antenna goes near to the rx inductor, the rx output gives a 10KHz square wave, that is what i want. but it has to be very close in order to get the signal. i mean the tx antenna has to be very close to the rx coil (less than or around 1cm only). can i increase the range by increasing the supply to the 555 timer? i can't increase the rx supply because i have to fix it in my robot using battery. thanks for all your helping.

 

your coil could have more than just one conductor. transmitter coil for AGVs using this type of guidance uses frequency in audio range (some 4-5kHz) and cable instead of wire. ends of cable ware terminated so that it appeared as multi turn coil. This part was done before I had chance to take a closer look but I think it was only some 4-5 turns (or conductors in cable). if more power is required to drive the coil you could use transistor after 555 chip. 555 is not very strong, don't stress it too much.

 

sorry. i really don't get the point..
what is " ur coil could have more than just one conductor"??
what is AGV??

and.. the last sentence, u mean i shouldn't increase the supplied voltage to increase the range? then what should i do? and what is the maximum voltage?
thanks for helping.

 

The max voltage and output current is listed on the datasheet for the 555.

__________________
Uncle $crooge

 

 

what do u think of this? should i make any changes in the circuit? :roll:
is there any problem with my receiving coil?

 

Can the circuit given by ruff be used as a buried wire fence for a robotic lawn mower? The mower has to move inside this wire fence only.

Thanks