I am a strong believer in try it for yourself. I have a youth group meeting tonight (DeMolay), so I won't be able to get back to it today.
You probably notice I'm trying to teach you how to think and design the circuit. Teaching is as much fun as designing. If you make a mistake it is no harm or foul, I just explain where I see a problem and show a solution. This is meant to be fun for everyone.
The only question I have is what I would label U3. A hysteretic circuit such as what is shown in the 555 Schmitt Trigger will have a dead zone between 1/3 and 2/3 volts. If you put the voltage ½ Vcc then it will act like a set/reset flip flop. The only problem is I don't know where it will power up. If it powers up the wrong way then I'll need to add a RC circuit on the reset pin (4) to automatically clear the chip during power up.
I hate adding extra parts, but sometimes you gotta.
I would use 555 chips for protoboarding, but if you plan on making a permanent version I would switch over to a dual 555, a 556, for the permanent copy. That way it would only be 2 chips.
The resistors on the Set FF can be large, as in 100KΩ. The LED I put on it is basically a simple diagnostic that can be eliminated later.
You probably notice I'm trying to teach you how to think and design the circuit. Teaching is as much fun as designing. If you make a mistake it is no harm or foul, I just explain where I see a problem and show a solution. This is meant to be fun for everyone.
The only question I have is what I would label U3. A hysteretic circuit such as what is shown in the 555 Schmitt Trigger will have a dead zone between 1/3 and 2/3 volts. If you put the voltage ½ Vcc then it will act like a set/reset flip flop. The only problem is I don't know where it will power up. If it powers up the wrong way then I'll need to add a RC circuit on the reset pin (4) to automatically clear the chip during power up.
I hate adding extra parts, but sometimes you gotta.
I would use 555 chips for protoboarding, but if you plan on making a permanent version I would switch over to a dual 555, a 556, for the permanent copy. That way it would only be 2 chips.
The resistors on the Set FF can be large, as in 100KΩ. The LED I put on it is basically a simple diagnostic that can be eliminated later.
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