Easy blinking LED circuit help please
Easy blinking LED circuit help please
(OP)
Hello all!
I need to construct a circuit that will cause an LED to selectively blink or stay on steady. The brightness needs to be adjustable and, when blinking, the rate of blink needs to be adjustable. The blink rate need only vary from about 1 second to about .25 second at 50% duty cycle.
I have found on the web a circuit made up of a 555 timer set up as an astable multivibrator with a few potentiometers to vary the blink rate and brightness and powered by a 9V battery. This works very well to blink the LED, but not being an electrical engineer, I'm not sure how to alter the circuit to make the LED stay on steadily.
The LED in question is rated at:
Forward Voltage: 2.4VDC +/- 0.3V (5VDC max)
Forward Current: 40mA max
Reverse Voltage: 6VDC
Power Dissipation: 100mW
Any ideas are appreciated.
SC
I need to construct a circuit that will cause an LED to selectively blink or stay on steady. The brightness needs to be adjustable and, when blinking, the rate of blink needs to be adjustable. The blink rate need only vary from about 1 second to about .25 second at 50% duty cycle.
I have found on the web a circuit made up of a 555 timer set up as an astable multivibrator with a few potentiometers to vary the blink rate and brightness and powered by a 9V battery. This works very well to blink the LED, but not being an electrical engineer, I'm not sure how to alter the circuit to make the LED stay on steadily.
The LED in question is rated at:
Forward Voltage: 2.4VDC +/- 0.3V (5VDC max)
Forward Current: 40mA max
Reverse Voltage: 6VDC
Power Dissipation: 100mW
Any ideas are appreciated.
SC





RE: Easy blinking LED circuit help please
RE: Easy blinking LED circuit help please
RE: Easy blinking LED circuit help please
If LED on when o/p is low then take 'thresh' pin low.
RE: Easy blinking LED circuit help please
RE: Easy blinking LED circuit help please
any blinking circuits that i can use on 1 watt LUXEONS with speed control?manual or preset.appreciate the help.
RE: Easy blinking LED circuit help please
RE: Easy blinking LED circuit help please
Astable should trigger the (retrigerable) monostable. Monostable should light LED.
By varying the frequency of astable, you adjust the blinking rate. If you adjust it very high, so that it retriggers monostable before it has time to go off, LED will never go dark. Additionally, while in blinking mode, you can regulate the brightness by varying monostable time constant, that is, the LED "on" time.
RE: Easy blinking LED circuit help please
site with schematic: http://www.play-hookey.com/digital/experiments/rtl_astable.html
just substitute the 1k resistor on one side for your led and series pot pot value of 1k would do well btw