haroldjclements
New Member
Hello forum,
I am new to electronics and have only a basic idea in the area. However, I am keen learner and have produced a nice little timer alarm using the classic NE555 device coupled with a Decade Counter to display the countdown using LED's. Pin 3 (Output 0) of the Decade Counter is attached to the first input of a NOR gate, and Pin 11 (Output 9) is connected to the other input of the NOR gate. The output of this NOR gate is connected to in 4 (Reset) of the NE555. Thus if the Decade Counter is on either outputs 0 or 9 the supply to Pin 4 of the NE555 is cut stopping the pulse (there is a manual switch to force the Counter to tick over).
The Problem: I am only getting just over 1 volt from 11 (Output 9) which is not enough to activate the NOR gate. I have tried adding a transistor to increase the voltage but (this is where my knowledge lets me down) I have been unable to make it work. I have also tried an OP AMP but again have failed to get any increase in voltage.
If anyone could help me by way of a small drawing or an easily understandable descriptive answer I would be very much obliged. I have read so much about transistors but just can't seem to get my head around it.
Thank you for your time,
Harold Clements
I am new to electronics and have only a basic idea in the area. However, I am keen learner and have produced a nice little timer alarm using the classic NE555 device coupled with a Decade Counter to display the countdown using LED's. Pin 3 (Output 0) of the Decade Counter is attached to the first input of a NOR gate, and Pin 11 (Output 9) is connected to the other input of the NOR gate. The output of this NOR gate is connected to in 4 (Reset) of the NE555. Thus if the Decade Counter is on either outputs 0 or 9 the supply to Pin 4 of the NE555 is cut stopping the pulse (there is a manual switch to force the Counter to tick over).
The Problem: I am only getting just over 1 volt from 11 (Output 9) which is not enough to activate the NOR gate. I have tried adding a transistor to increase the voltage but (this is where my knowledge lets me down) I have been unable to make it work. I have also tried an OP AMP but again have failed to get any increase in voltage.
If anyone could help me by way of a small drawing or an easily understandable descriptive answer I would be very much obliged. I have read so much about transistors but just can't seem to get my head around it.
Thank you for your time,
Harold Clements