Hi, I have a simple project to make, but I don't know how. I have to make circuit with a simple LED for blinking at different frequencies. I have a signal generator connected to PNP 2N3906G transistor, the LED does not even turn on. anybody has any circuit schematic or can guide me, will be really appreciated.

 

http://www.allaboutcircuits.com/vol_6/chpt_8/5.html.

 

I was the author of that particular article, you will find folks will be glad to help design to what ever specifications you give, provided you are complete in your descriptions. The article shown is based around Radio Shack parts, there are many ways to skin this particular cat.

 

thanks for the link. Is there anyway I can do it with a transistor and a function generator? these are the only things I have right now, and this is just a project to help someone decide the speed of blinking.

 

What is your power supply (or battery) voltage?

 

I have bench power supply (5 v/10v)

 

If your function generator has a 50 ohm output resistance, it can drive an LED directly.
You can use a transistor, if you still want to.

 

Thanks Ron, the LED is on now, but not blinking, the function generator is set as Step, Amp 5v (Vpp) and frequecy 10Hz, DC offset at 0.

 

Problem solved, I checked my cable from function generator and it was not 50 ohm cable, I changed it and it is blinking now. I appreciate your help.

 

Now I have another question, how can I make an asymmetric flashing LED, I mean if I want the LED to be on for 1 second and off for like two seconds how can I make it?

 

Now I have another question, how can I make an asymmetric flashing LED, I mean if I want the LED to be on for 1 second and off for like two seconds how can I make it?

Your function generator should have a duty cycle or symmetry adjustment knob. What kind of function generator do you have?