k7elp60
Active Member
This is a circuit that may do what MR. Deb wants.
1/2 of the 556 operates as a one-shot when triggered by a negative trigger from the PIR. The one-shot is high for about 11 seconds and turns on the other half of the 556 which is a astable with a high period of 2 seconds and a low period of 2 seconds. On PIEZO is on when the astable is high and the other one is on when the astable is low.
1/2 of the 556 operates as a one-shot when triggered by a negative trigger from the PIR. The one-shot is high for about 11 seconds and turns on the other half of the 556 which is a astable with a high period of 2 seconds and a low period of 2 seconds. On PIEZO is on when the astable is high and the other one is on when the astable is low.