Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

How to build an ASK Modulator ?

Status
Not open for further replies.

hay2night

New Member
Hi guys,

I have to make a project for school based on X10 protocol theory.
What i have to do is to build two circuits that can transmit and a receive bits over the electrical power lines.

I have found some useful materials about that but i have a problem that i cant resolve at this time.
I don't know how to build an ASK modulator (which i'm gonna use in the transmiter circuit)The modulator signal comes from a microcontroller (bits ) and the carrier is a sine wave at 100KHZ. :confused:

Can u help me please with a scheme for the ASK modulator ?? (A light one that i'll be able to undersand)

Thanks a lot
 
Can you do on/off shift keying (it's a form of ASK) or do you need a true two level ASK?
 
Yes...i can use on /off shift keying.That's ok
I have been told that i can use a transistor to do that but i don't know yet.

Can you tell me how or can you put here a circuit please ?
Thank you.
 
ASK modulation is prone to many problems, such as noise. Considering that your using X10 I assume your using power lines in which case there will be lots of noise, many errors. Perhaps a different modulation scheme should be used.
 
Thanks for advice but I told you that I am a newbie in electronics although I study it at school.:D
I have to do a modulation of a sine wave(100KHz) with bits coming from a uC like i said.(where is "1" there will be a presence of the sine , where is "0" there will be an absence of the sine....isn't it good ?)
I am not constrained to use ASK , but i believe it's the easiest possible type.
I must tell you that i want the receiver to use bandpass filtering to extract the signal not a kind of complex demodulator.

Thanks.
 
Thanks for advice but I told you that I am a newbie in electronics although I study it at school.:D
I have to do a modulation of a sine wave(100KHz) with bits coming from a uC like i said.(where is "1" there will be a presence of the sine , where is "0" there will be an absence of the sine....isn't it good ?)
I am not constrained to use ASK , but i believe it's the easiest possible type.
I must tell you that i want the receiver to use bandpass filtering to extract the signal not a kind of complex demodulator.

Thanks.

The BPF does not extract the signal, it only limits out of band noise. You will have to use a demodulator in any case. I would suggest PSK modulation as this is less affected by noise. Consider AC power is a very noisy environment, and noise will affect the signal.
 
Mikebits : You're right. There was an amplitude detector in my scheme at the receiver :D (which is a demodulator)
How to use PSK ? :D
Do you have a helpful link or book or scheme ?:)

Thank you
 
Try here.
**broken link removed**
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top