hi i need your help once again guys. i am working on my project and i took the suggestion of the SIGNAL DETECTING AUTO POWER ON UNIT. BY ELLIOT PROJECT 38. but now i am facing a challenge of coming up with a circuit which will allow the input signal unit to be on but when the signal is switch off the device also should be switched off from the mains supply. so that when in the absence of a signal the whole project including the input signal device eg audio cassette player should be turned off. i will appreciate if any suggestions will come up since i have only 2and half weeks to finish the project.