Transcript MILK PLASTIC!

Monostable &
Astable Circuits
Starter, What Pin am I!
Work in groups of 3 - 4
Rules;
Start with the oldest or youngest, aim is to fill out the table you have, first one to fill
it out wins. Electronics BINGO!
1. Deal cards face down, then look, don’t show the others! Keep close to your chest!
2. Reveal cards; Use wisely, this will force a player to reveal one of there cards to the
group.
3. Ask questions to find out the pin someone else has, the player you ask can only
answer Yes or No.
4. Steal Card; You can steal any players card!
Look at the circuit diagram to help you work out the function
Starter, What Pin am I!
Pin 1;
Pin 2;
Ground (OV)
Trigger
Function;
Function;
Connects to the OV
power supply.
A short low (less than 1/3 Vcc)
pulse on the trigger starts the
timer. By connecting this to
ground we "turn on" the 555
timer.
Pin 3;
Output
Function;
Goes high & Low,
pulsating output.
Starter, What Pin am I!
Pin 6;
Pin 4;
Pin 5;
Reset
Control
Threshold
Function;
Function;
Function;
Forces Pin 3 low if
pulled to ground.
A voltage to this pin will
vary the timing of the
RC network (quite
considerably).
Is controlled by pin 2.
The pulse ends when
the voltage is greater
than the control.
Starter, What Pin am I!
Pin 7;
Pin 8;
Discharge
Supply
Reveal;
Function;
Function;
Controls timing, open
collector output; to
discharge capacitor.
Connects to positive
power supply.
Typical range 4.5v to 16v.
Reveal one card to all
the players
Starter, What Pin am I!
Starter, What Pin am I!
Steal;
Take another players
card! Anyone’s!
Cheeky! Now you can
fill out a function!
Fill Out worksheet as you go!
Pin Num
Function
Name
1
2
3
4
5
6
7
8
What’s my purpose in life!
Do you remember!
Name;
Date;
Pin Num
1
2
3
4
5
6
7
8
Function
Name
Pin Num
Function
Name
1
2
Connects to the OV power supply.
Ground (OV)
A short low (less than 1/3 Vcc) pulse on the
trigger starts the timer. By connecting this to
ground we "turn on" the 555 timer.
Trigger
3
Goes high & Low, pulsating output.
Output
4
5
Forces Pin 3 low if pulled to ground.
Reset
A voltage to this pin will vary the timing of
the RC network (quite considerably).
Control
6
Is controlled by pin 2. The pulse ends when
the voltage is greater than the control.
Threshold
7
Controls timing, open collector output; to
discharge capacitor.
Discharge
8
Connects to positive power supply.
Typical range 4.5v to 16v
Supply