I have a few questions about this schematic...
**broken link removed**
First.. I don't see a power source for the receiver.
Also, the secton of the receiver with the leds, doesn't that need a ground somewhere? I only see one wire going to all of that..
Please, someone look over it and tell me if they think it will work. I am pretty new to making this kind of thing... so I don't really know much about it.
What I am actually looking for, is a way to transmit an RF, up to 100 feet or so, and a reciever that only needs to be able to know whether the signal is present or not.
Neither do I... That's really wierd, the positive is grounded also, hmmm... I think someone screwed the pooch with this one, or made the thing backwards, the negative should normally be grounded... that's really wierd...
The transmitter is not the best design but it will work. But from the inductor value shown it will transmit in the long or medium wave broadcast bands, so it will be difficult to detect among all the high-powered stuff being broadcast there.
The receiver will never work - even with the correct power supplies. There is no form of detection - such as a diode - and the 741 is just operating as an amplifier. It could amplify audio frequencies OK but there is no way it can deal with frequencies in the broadcast bands. It was never designed for that.
If you want to make such a device, do a Google search for FM transmitters and receivers. There are plenty of them published.
I can't see mentioned anywhere how this car locator works.
Is the transmitter fitted in the car and switched on at all times when you have parked the car, and you carry the receiver?
I think you could have trouble getting any meaningful information from the number of LEDs lit up. In a car park the transmitted signal is reflected many times by the metal of all the cars and you can end up with 'dead spots' where you can get no signal, so the LED indication would change as you move about. And how do you know in which direction to go towards your car?
If many people use these devices you could end up by finding the wrong car. :?
If you want to purchase modules to make up the transmitter and receiver then do a Google search for RF Solutions. I think they are international and their bits are sold in the UK by RS, Maplin and probably Farnell. These modules operate in the bands 418 to 434MHz.
Yes, I realize there are many things wrong with it, even if the schematics did work. However, as I said before.. this is not my intended use for the device.
I have been looking around for different RC moduels, and found these:
**broken link removed**
Today cannot found a pure frequency,except on GHz-band. My opinion:hopeless to found a car without directional aerial and receiver with hand variable sensitivity. (think about "fox-hunting" sport)
I have a few questions about this schematic...
**broken link removed**
First.. I don't see a power source for the receiver.
Also, the secton of the receiver with the leds, doesn't that need a ground somewhere? I only see one wire going to all of that..
Please, someone look over it and tell me if they think it will work. I am pretty new to making this kind of thing... so I don't really know much about it.
Dear TAF,
There two lines comming out of the led's aren't there try using the line comming out of the flat side (The side with the horazontal line) as base.
Thanks