Light chaser

[davit]

hi
as per pic i have this light chaser kit which i assembled and it worked ( strange for me )
i am using it with 2 leds on each line out which also seems ok,
But would anyone know if its possible to add a switch somewhere to this circuit board so all the leds
can stay on, i just need that switch able option for my project , also would ( if thats posible ) it overload any component
thanks for looking
davit

 

[duke37]

I think it would be easier to use 10 more leds each with a resistor and switch to your battery.
You will not need more leds if you use steering diodes (two per led)
Will the battery be able to supply the current for ten leds in parallel?

 

[Audioguru]

The Chinese schematic is wrong:
1) The minimum supply voltage for the NE555 is 4.5V so it might not work at 3V to 4.5V.
2) The output current from a CD4017 is only 3mA into an LED without a resistor when its supply is 5V and the current is less at lower voltages. Then the resistors are not needed and the LEDs will be dim. The LEDs will be much brighter when the supply is 9V and resistors are needed if the supply is more than 9V.

For a supply voltage as low as 3V a Cmos 555 (LMC555 or TLC555) and a 74HC4017 High current Cmos ICs should be used.

 

[davit]

thanks for the replys
i am using 5v and its working ok just wish i could fit a switch so
they stay when i need them to
thanks guys

 

[kellys_eye]

You can gate the signal from the 555 to the 4017 to interrupt the clock and keep the LED status 'as-is' - equally you could switch the 'clock inhibit' line of the 4017 (pin 13) to achieve the same result.

 

[davit]

You can gate the signal from the 555 to the 4017 to interrupt the clock and keep the LED status 'as-is' - equally you could switch the 'clock inhibit' line of the 4017 (pin 13) to achieve the same result.

wow that sounds good , i cannot see these lights as they are on the front of a car ( not road use ), could you give me a dummies guide to fit a switch to the 4017, do you mean just fit a switch to break that connection at any time and they will all stay on,
thanks
davit

 

[Audioguru]

A CD4017 lights only one LED at a time. It will never make them all stay on. You can "inhibit" the clock then the LED that was lighting stays turned on and the remaining LEDs will all be off.

To switch them all on you would need two diodes for each LED, one of the diodes from the CD4017 and the other diode from the switch. Then the LEDs driven by the CD4017 will be even dimmer.