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transmitter & receiver circuit problrm

Posted: Fri Apr 04, 2014 10:21 pm
by tefaelgn
Hello , iam serious to build this circuit and i do that exactely , but it's not work :(

i used torid core with 5 turns of magnetic wire has cross section area of 0.5mm .. and replace the 1uH to 5uH ( i can not catch the 1uH so replace it ) and i used 2M ohm insted of 2.2M ohm ... and timer NE555 insted of 7555 .... and i used coaxeal cable for antenna ..

is this replacement make the circuit to do not work ??

sorry for Prolongation .

i will be on with you until the circuit working with me :) :) :D

thx.

Re: transmitter & receiver circuit problrm

Posted: Fri Apr 04, 2014 11:18 pm
by ThePyroElectro
tefaelgn wrote:Hello , iam serious to build this circuit and i do that exactely , but it's not work :(

i used torid core with 5 turns of magnetic wire has cross section area of 0.5mm .. and replace the 1uH to 5uH ( i can not catch the 1uH so replace it ) and i used 2M ohm insted of 2.2M ohm ... and timer NE555 insted of 7555 .... and i used coaxeal cable for antenna ..

is this replacement make the circuit to do not work ??

sorry for Prolongation .

i will be on with you until the circuit working with me :) :) :D

thx.


Hello,

Those changes should be ok.

The easiest way to trouble-shoot the circuit is to use a spectrum analyzer to make sure your transmitter is transmitting at the correct frequency and that it has decent power output.

When you know for sure that is working, you can use an oscilloscope or spectrum analyzer after the tuning circuit and front end on the receiver to see if the signal is getting through.

Please see my project write-up to see how the signal should look at those different points.

I will bet that your RF coil + capacitor are not tuning for the correct frequency.

Re: transmitter & receiver circuit problrm

Posted: Sat Apr 05, 2014 5:02 pm
by tefaelgn
thx for fast answer

i already test it on the simulation program . almost all point that you shown in the explaination for test on oscilloscope appear the same waveform like in your pictures , ONLY one point dosen't operate well , this point is the first point for the crystal , in my simulation the crystal not oscillator and i don't know why!!!

i forgot to tell you that i use crystal 27MHz only and not 27.145MHz like yours .

i will try again and tell you the new results .

thx.

Re: transmitter & receiver circuit problrm

Posted: Sat Apr 05, 2014 9:03 pm
by tefaelgn
this is receiver circuit:
receiver.JPG
receiver.JPG (71.92 KiB) Viewed 9815 times


and this is transmitter circuit:

Re: transmitter & receiver circuit problrm

Posted: Sat Apr 05, 2014 9:09 pm
by tefaelgn
power supply for 5v and 9v
power.JPG
and this is power supply for 5v and 9v
power.JPG (34.6 KiB) Viewed 9815 times


and this is the coaxial cable that i used.
coaxeal cable.JPG
and this is the coaxial cable that i used.
coaxeal cable.JPG (91.3 KiB) Viewed 9815 times

Re: transmitter & receiver circuit problrm

Posted: Sun Apr 06, 2014 10:26 pm
by ThePyroElectro
Hi Tefaelgn,

I don't expect that this circuit will work on a breadboard, you really should build it on a PCB.

Simulating a crystal, at least in PSPICE, can be a little tricky because the models in most SPICE programs need to be 'jump-started' before they will begin to oscillate as part of the sim.

Re: transmitter & receiver circuit problrm

Posted: Mon Apr 07, 2014 1:24 pm
by tefaelgn
OK . let's go to the layout and PCB to desgin the two circuit,,,

before that , i want to show you the components that iam soldering it .

for transmitter circuit :
circuit diagram 2 with some variation.png
circuit diagram 2 with some variation.png (48.17 KiB) Viewed 9805 times


for receiver circuit :

Re: transmitter & receiver circuit problrm

Posted: Mon Apr 07, 2014 1:32 pm
by tefaelgn
ah .. one question for antenna >>>

i can use any wire for it or i should use a specific one ?? i can use the wire of utb cables ?

Re: transmitter & receiver circuit problrm

Posted: Mon Apr 07, 2014 7:30 pm
by tefaelgn
iam sorry i forgot to add this altrnative to the receiver circuit .

Re: transmitter & receiver circuit problrm

Posted: Tue Apr 22, 2014 10:46 pm
by tefaelgn
sorry for the delay.

this is my layout for transmitter circuit

Re: transmitter & receiver circuit problrm

Posted: Wed Aug 27, 2014 11:24 pm
by tefaelgn
hello
i back again :)
i built the PCB for the two citcuit (Tx and Rx)... i can recive the signal but it is very weak ... and looklike a flasher ... when i press the putton in the Tx circuit, the green LED don't emit > but when leave the button the green led emit little light and close .

maybe the amplifier in Rx circuit have a problem??
i wait your advice .
thanks.

another question : your Tx circuit can run with any Rx circuit or must use your Rx circuit ?