I can see a few problems with the schematic in post #7
1 - There is nothing to limit the current through the LEDs so you are likely to exceed the current rating of the LEDs or the 200 mA maximum current rating of the 555s.
2 - The two red LEDs in series will tend to clamp the voltage to about 3.6 volts ( 2 x 1.8 volts.) As these are connected in parallel with two blue LEDs in series the blue LEDs will not light as they will need about about 6 volts (2 x 3 volts)
You need two current limiting resistors. One for the red LEDs and one for the blue LEDs. The values need to be to be calculated to give the required currents through the LEDs.
I am not convinced that the light output from the LEDs will be enough for use in daylight. (Assuming that you are running the 555s at their maximum output current rating of 200 mA and you have 100 mA through the red LEDs and 100 mA through the blue LEDs the power input to the red LEDs will be 0.36 watts and the power input to the blue LEDs will be 0.6 watts)
3 - U1 will not oscillate as there is nothing to discharge the timing capacitor. You need to connect pin 7 to the top end of C2
Edit. I am was wrong about point 3. I now see that the top end of R3 is connected to U1 output. (I was assuming it was connected to + 12 volts.)
Les.
1 - There is nothing to limit the current through the LEDs so you are likely to exceed the current rating of the LEDs or the 200 mA maximum current rating of the 555s.
2 - The two red LEDs in series will tend to clamp the voltage to about 3.6 volts ( 2 x 1.8 volts.) As these are connected in parallel with two blue LEDs in series the blue LEDs will not light as they will need about about 6 volts (2 x 3 volts)
You need two current limiting resistors. One for the red LEDs and one for the blue LEDs. The values need to be to be calculated to give the required currents through the LEDs.
I am not convinced that the light output from the LEDs will be enough for use in daylight. (Assuming that you are running the 555s at their maximum output current rating of 200 mA and you have 100 mA through the red LEDs and 100 mA through the blue LEDs the power input to the red LEDs will be 0.36 watts and the power input to the blue LEDs will be 0.6 watts)
3 - U1 will not oscillate as there is nothing to discharge the timing capacitor. You need to connect pin 7 to the top end of C2
Edit. I am was wrong about point 3. I now see that the top end of R3 is connected to U1 output. (I was assuming it was connected to + 12 volts.)
Les.
Last edited: