Can someone provide me a simple timer schematic?
Posted: Fri Sep 10, 2004 11:54 pm
I've learned some stuff since I last posted here, and I feel I am ready to start working on schematics now. I have a good grasp on Ohm's Law, resistance, capacitors, symbols and stuff.
I was at my local Radio Shack the other day, and they had cheap ICs on clearance, so I picked up 5. They are all CMOS high-speed logic chips.
Anyway, I'm not sure if any of them will control an LED. I need a simple circuit that utilizes a 555c timer that counts seconds 0-9 and displays them on an LED. If you need the specs on my 555c timer and LED, I can provide them.
Radio Shack #: 276-1723 555CN timer:
18V max
4.5-16V typ.
power dissipation: 600mW
Output current (sink or source): 200mA
276-075 LED max ratings:
Forward current: 30mA
Forward voltage: 2V
Reverse voltage: 5V
Power dissipation: 100mW
Typical:
Forward current: 20mA
Forward voltage: 1.7V
Peak wavelength: 655nm
Here is the model number/series of one chip in particular. 74HCT541 Octal Buffer/Line driver; 3-state. I am not sure if this would make the LED work or not.
All I want to learn from this project is how to make an LED work, as well as actually using the timer. Thanks alot.
I was at my local Radio Shack the other day, and they had cheap ICs on clearance, so I picked up 5. They are all CMOS high-speed logic chips.
Anyway, I'm not sure if any of them will control an LED. I need a simple circuit that utilizes a 555c timer that counts seconds 0-9 and displays them on an LED. If you need the specs on my 555c timer and LED, I can provide them.
Radio Shack #: 276-1723 555CN timer:
18V max
4.5-16V typ.
power dissipation: 600mW
Output current (sink or source): 200mA
276-075 LED max ratings:
Forward current: 30mA
Forward voltage: 2V
Reverse voltage: 5V
Power dissipation: 100mW
Typical:
Forward current: 20mA
Forward voltage: 1.7V
Peak wavelength: 655nm
Here is the model number/series of one chip in particular. 74HCT541 Octal Buffer/Line driver; 3-state. I am not sure if this would make the LED work or not.
All I want to learn from this project is how to make an LED work, as well as actually using the timer. Thanks alot.