Hello everyone its been a long time since I posted here, been 2 year member . Anyways me and another user on here won a spot to present at a Youth Entrepreneurship challenge and we need to make a demonstration of our product. Basically it needs to be radio controlled device that can control a camera flash circuit and detect signal strength and beep when the strength gets to below a certain point.
We are thinking of the pager circuit for our radio controller since phones work off of FM signals and a homemade field meter for signal detector. As for the beep were using a simple piezo buzzer. The question is will the field meter pick up a phone frequency? And if so how could we make it activate a switch on the buzzer circuit?
Radio Controlled Shock Device
-
- Corporal 5
- Posts: 986
- Joined: Thu Jun 16, 2005 1:44 pm
- Been thanked: 1 time
The challenge here is that modern cordless phones work in the microwave band. Therefore you'll have to deal with all the extra issues that come up with using high frequencies.
You could also just build an FM transmitter yourself pretty easily. I've seen alot of schematics around on Google, and they don't look too hard. That being said, I've never tried it myself.
You could also just build an FM transmitter yourself pretty easily. I've seen alot of schematics around on Google, and they don't look too hard. That being said, I've never tried it myself.
"If at first you dont succeed, then skydiving is not for you" - Darwin Awards
-
- Corporal 5
- Posts: 986
- Joined: Thu Jun 16, 2005 1:44 pm
- Been thanked: 1 time
Well, directly, probably not..but it can be modified quite easily.
Here is my one somewhat useful contribution to this site, it will let you use the speaker output from any device (provided the output is>0.7V) to trigger a relay: http://www.spudfiles.com/forums/the-pho ... 12578.html
Here is my one somewhat useful contribution to this site, it will let you use the speaker output from any device (provided the output is>0.7V) to trigger a relay: http://www.spudfiles.com/forums/the-pho ... 12578.html
"If at first you dont succeed, then skydiving is not for you" - Darwin Awards
- paaiyan
- First Sergeant
- Posts: 2140
- Joined: Wed Dec 27, 2006 10:03 pm
- Location: Central Oklahoma
- Been thanked: 1 time
This guy on instructables made a device that sounded an alarm when a light source was interrupted, you could do something similar. Here's the link.
"Who ever said the pen was mightier than the sword, obviously, never encountered automatic weapons."
-General Douglass MacArthur
Read my dog's blog - Life of Kilo
-General Douglass MacArthur
Read my dog's blog - Life of Kilo
-
- Corporal 5
- Posts: 986
- Joined: Thu Jun 16, 2005 1:44 pm
- Been thanked: 1 time
Unfortunately, I can't really think of a way to measure signal strength without making it a duplex system of one sort or another. You'd probably need another transmitter on the receiver.
"If at first you dont succeed, then skydiving is not for you" - Darwin Awards
-
- Corporal 5
- Posts: 986
- Joined: Thu Jun 16, 2005 1:44 pm
- Been thanked: 1 time
Alrighty then, make a transmitter on your "receiver", and just keep it constantly transmitting something or another.
Now, on your "transmitter" side, you'll want to add a chip that detects RF signal strength. I know they exist because my buddy built one, but I don't know exactly what chip it is.
Should be pretty simple from there.
Now, on your "transmitter" side, you'll want to add a chip that detects RF signal strength. I know they exist because my buddy built one, but I don't know exactly what chip it is.
Should be pretty simple from there.
"If at first you dont succeed, then skydiving is not for you" - Darwin Awards