mc145026
i want to make a 4-bit radio control. i searched the circuit design and i got the one in which TWS/RWS RF modules are used.. can you tell me how can i make the circuit without using the modules? i've made FM tramitter and receiver circuits.. which generates the signals but at the receiving end MC145027 does not recognize the signals.. do i have to use the Analog to digital converter? or is there any other design which i can use.. please help me
hello
The output of the MC145026/27 is digital pulse if you want to use it with an Fm transmitter you have to modulate the input signal e.g use of FSK modulator
Remember that you have to dmodulate the signal as well.
The easy way is to use an ASK or AM type of transmitter isted of FM less complicated.
All the best
Bobi
i even tried with the AM transmitter type.. it still doesn't work.. do u have any circuit design of an AM transmitter and receiver which can be used with those ICs? or is there any other way out?
Hi
Dont build a trasmitter or a receiver it's to complicated buy one it's low cost
and easy to use use : www.digikey.com
All the best
Bobi
But i want to build one of my own! i dont have a credit card to order one on the internet.. and its not available here in the market! so building one of my own would be the easiest way! if you have the design then plz let me know! do i have to use the ASK modulator/demodulator with the AM transmitter as well?
Hi
Here is a link to RFM site where you can find lot of app note on discrate transmitter
and receiver design
http://www.rfm.com/corp/apnotes.htm
All the best
Bobi
thats a very complicated stuff! can't get it at all! i'll describe the whole situation again..
see i have made a signal generator circuit with MC145026.. and i also have simple FM transmitter ciruit which can transmit the voice.. on the other side.. i have MC145027 circuit which can read the signal and give output.. and i also have the FM receiver circuit.. but by connecting all those i can't get MC145027 to work through transmitter/receiver.. n i guess its not supposed to work becuz MC145026/27 generates/understands the digital signals..
specifically wht component(s) can i use to get all these things to work.. can u please explain it further for me? im confused :(
Hi
You will need to modulate the digital signal using FSK look for a chip 74HC4060 PLL
or LM567
As I say befor modulating the digital signal will complicat your design there for i recomend you to use ASK
All the best
Bobi
using ASK will eliminate the need for modulation? do u mean to say if i use AM transmitter/receiver i can directly connect the MC145026/27 ICs with them? and they will work? if not then how can i make them work even with the AM trans./receivers ? like which component(s) to use with them?
Hi
Yes ASK is the easy way to use you don't need to modulate the signal only connect the MC145026/027 directly
All the best
Bobi
thanks it worked! but i need a simple and longer range AM transmitter and receiver like around 100metres.. can you give me a circuit diagram? or any url? i searched it on the net but couldn't find a good one!
Hi
If you need to increase the range there is 2 way to do that :
1) Increase the transmited power - connect a MMIC amp like the MAR amps from mini-circuit look at : www.minicircuit.com - but it's not ligal to do
2) Get a good high senstivity receiver with at lest -100 dbm senstivity
All the best
Bobi
can u give me some simple design for AM transmitter/receiver?
Hello
I enclose a simple circuit of Reciver & transmitter for the 433 MHz band
All the best
Bobi
the led in the receiver circuit connected with 7th pin of IC through a resister.. is it supposed to light when the signal is received? or it will remain on? cuz when i made the circuit it doesn't go off! while the LED in transmitter goes on only when signal is sent.. :(