Urgent help for led load

Thread Starter

shyckh

Joined Jul 28, 2014
26
HHi i want to blink 2 set of leds each containg 16 leds each. These leds must blink out of phase with respect to each other. I have used monostable osscilator (555 timer) and give the output to 1 set of led.also i have used an inverter at the output of Timer. The output of inverter is given to other set of led. The intencity of 2nd set is very low. Need help how to increase the power. What values of resistance should i used to get enough power to light up these leds. Any other suggestion will also be appreciated. See the circuit diagram of inverter also. Thanks
 

Attachments

wayneh

Joined Sep 9, 2010
17,498
Your attachments are identical. Do you have other transistors to choose from, or are you locked into one particular model?

That's an inefficient way to accomplish the inversion. Let's come up with something better.
 

Thread Starter

shyckh

Joined Jul 28, 2014
26
Your attachments are identical. Do you have other transistors to choose from, or are you locked into one particular model?

That's an inefficient way to accomplish the inversion. Let's come up with something better.
Tell me how can i make it more efficient??
 

wayneh

Joined Sep 9, 2010
17,498
Switch the current in the second bank of LEDs exactly as you do the first, using the transistor as the control over the return to ground. But connect the base of the second transistor to the collector of the first. This will turn the 2nd transistor on when the 1st is off, and vice versa. You'll want the appropriate resistor on the base of the 2nd transistor, to limit the base current to 10% of the current used by the LED bank.
 

Thread Starter

shyckh

Joined Jul 28, 2014
26
Switch the current in the second bank of LEDs exactly as you do the first, using the transistor as the control over the return to ground. But connect the base of the second transistor to the collector of the first. This will turn the 2nd transistor on when the 1st is off, and vice versa. You'll want the appropriate resistor on the base of the 2nd transistor, to limit the base current to 10% of the current used by the LED bank.
If you can draw the circuit diagram for me for better understanding. It should be a great help
 

Thread Starter

shyckh

Joined Jul 28, 2014
26
Switch the current in the second bank of LEDs exactly as you do the first, using the transistor as the control over the return to ground. But connect the base of the second transistor to the collector of the first. This will turn the 2nd transistor on when the 1st is off, and vice versa. You'll want the appropriate resistor on the base of the 2nd transistor, to limit the base current to 10% of the current used by the LED bank.
Oh ! You are saying to connect transistor in cascaded way,????
 

Thread Starter

shyckh

Joined Jul 28, 2014
26
Or you can use this circuit
View attachment 72902
And are you sure that you don't need astable gen ?
Yes iam sure i dont need astable gen... But this circuit will solve power issue but one set of led will flicker so rapidly so that my software dose not detect its flickering. Any way to slow down the switching speed??? Leds attached to 555 tiner has been detected by the software but other set has not been detected
 
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