hello,
I am building something for wich I need to control 156 leds in 26 strings of 6. I need to be able to dim them both automatically and manually. In automatic mode they should become brighter when there is more ambient light. To do this I am using a 555 timer circuit and a potentiometer/LDR.
I think I have made a working circuit but it would be nice if someone could check for any errors before I start ordering components.
For R1 I used 0,693 * 47.000Ω * 0,000.000.01F. this gives me a charging time of 0,0003257 seconds
For the discharging time I used the same formula with the potentiometer at 5kΩ and have gotten a maximum discharging time of 0,003465 seconds. This would mean the leds would only be on for about 10% of the time.
The ldr has a light resistance of 16kΩ and a dark resistance of 0,5MΩ, so it should give about the same result as with the potentiometer I think.
I am building something for wich I need to control 156 leds in 26 strings of 6. I need to be able to dim them both automatically and manually. In automatic mode they should become brighter when there is more ambient light. To do this I am using a 555 timer circuit and a potentiometer/LDR.
I think I have made a working circuit but it would be nice if someone could check for any errors before I start ordering components.
For R1 I used 0,693 * 47.000Ω * 0,000.000.01F. this gives me a charging time of 0,0003257 seconds
For the discharging time I used the same formula with the potentiometer at 5kΩ and have gotten a maximum discharging time of 0,003465 seconds. This would mean the leds would only be on for about 10% of the time.
The ldr has a light resistance of 16kΩ and a dark resistance of 0,5MΩ, so it should give about the same result as with the potentiometer I think.