50% Output Duty Cycle

The LM555 timer can achieve a 50 percent duty cycle as shown in the next diagram. The duty cycle adjustment range of the give components values is from 42 to 55 percent.
Resistors R1 and R2 were selected first and then resistor R3 was selected to give the best control range based on measurements at the output of the timer.
The major disadvantage of using the LM555 in this manner is that the output frequency changes as the duty cycle changes. [...]
Read more Source: http://home.cogeco.ca/~rpaisley4/LM555.html

Power Supply   Switching Power Supply   DC to DC Converter   Inverter
Battery charger   Led flasher   Motor speed controller   LM317   IC 741
RF radiofrequency   Electronic control   Digital Circuit   Alarm home system
DC to DC converter step up voltage   Mini project   Temperature control
FM receiver   Dual power supply   Fluorescent lamp   Pic microcontroller
Led display   RF amplifier   FM transmitter   LM324   LM723   TL494
2N3055   LM338   SG3525   Li-ion battery charger   Pulse generator