change voltage output levels as well as current ratings. Note with larger currents that you should provide a heat sink on Q1. To change the maximum voltage output, use the formula:
Vout =5*(1 + R2/R1)
There are plenty of ways to use the outputs of the URC1 to control different circuits, devices, and run equipment. These basic ideas given will get you started on developing your own remote control system. If you want more ideas or more detail on how to hook up these circuits, consult some of the electronics magazines available at the supermarket, or go to your local library. These sources are usually loaded with great ideas for interfacing the types of output provided here with the external world!
Building a Telephone Audio Tap:
Through this method the user can tap the DTMF tone off of a telephone line. This is the simplest of methods to interface the URC1 to the telephone lines. Notice though you will need some sort of answering device such as a message machine to pick up the phone. If the phone is not off the hook, this circuit will not pick up any audio.
Inserting Audio output into the phone line:
To J1 Tone in
This is how you are able to insert the confirmation tones into the telephone line so that when you are dialing from a remote location you can hear the URC1 talk back to you, and let you know that a code was correctly received and processed. You may also receive tones as well with this circuit. Notice it is in parallel with the phone line instead of series like the previous circuit.