Help with switching LEDS
I have built a knight rider type circuit using a 555/74193 and 74154.
I have used half of the o/p's of the 154 to "count up" and the second half to "count down"
This works fine if all you want to use is 1 or 2 led's, lighting each one in turn like "kitt" does in the tv program.
In this configuration the circuit will light 1 led in turn and extinguish the one it has just lit, etc up to nine and then repeat itself.
See attached schematic.
I have been given an idea that will do the complete opposite to the above IE
LED1 is off and the rest are ON
LED2 is off and the rest are ON ,,,, etc up to LED9 then it repeats.
Can anyone give me an idea how to achieve this idea and it has to be capable of driving between 13 and 17 LEDS.
The reason for so many LEDS is that they will make up letters of the alphabet.
I have found many schematic’s that will light multiple LEDS in a switch on configuration but NONE that will keep them on with a momentary OFF
CAN anyone HELP me PLEASE
PLZ reply with a schematic as I find them easier to follow
Many thanks in advance Steve
I have built a knight rider type circuit using a 555/74193 and 74154.
I have used half of the o/p's of the 154 to "count up" and the second half to "count down"
This works fine if all you want to use is 1 or 2 led's, lighting each one in turn like "kitt" does in the tv program.
In this configuration the circuit will light 1 led in turn and extinguish the one it has just lit, etc up to nine and then repeat itself.
See attached schematic.
I have been given an idea that will do the complete opposite to the above IE
LED1 is off and the rest are ON
LED2 is off and the rest are ON ,,,, etc up to LED9 then it repeats.
Can anyone give me an idea how to achieve this idea and it has to be capable of driving between 13 and 17 LEDS.
The reason for so many LEDS is that they will make up letters of the alphabet.
I have found many schematic’s that will light multiple LEDS in a switch on configuration but NONE that will keep them on with a momentary OFF
CAN anyone HELP me PLEASE
PLZ reply with a schematic as I find them easier to follow
Many thanks in advance Steve
Attachments
Last edited: