K8064 - Please help. Red light, four flashes


I’ve recently taken up electronics and have soldered up the K8064 kit with the aim of dimming an CFL bulb, running off 240V mains here in Australia. Ultimately I am hoping to provide DC control using an Arduino.

I connected the K8064 to mains with the CFL bulb and received 4 red flashes. As per the error instructions I changed bulbs just in case the CFL was out of phase. I retried with an incandescent bulb and had the same problem.

Please see attached link to images of the top and bottom of the board as well as an overview image: http://imgur.com/a/GwQvT

I would appreciate any advice and support.

Many thanks!

It will be very hard to dim an CFL bulb with this dimmer because this dimmer normally can’t do this. It should however work with an incandescent lamp although it is possible that your CFL bulb did something very nasty and damaged the K8064.

Thanks for your thoughts laserguy. Can you recommend a way to test if I have in fact damaged the circuit in order to replace the part/s?

Can anyone recommend an alternative way to dim a CFL using Arduino?

Does it have to be CFL? I read that some of the newer LED bulbs behave nicely with TRIAC based dimmers. Find reviews of the exact model “before” you buy. Some are said to produce the same humming noise that many dimmable CFLs have.

No it doesn’t MostlyHarmless. I was figuring I’ll try and design the circuitry for the most common dimming bulbs available but if I have to limit to one style then so be it.

Can anyone recommend an alternative way to dim a CFL using Arduino?

Velleman Support, can you recommend a best way fault check the circuit?


Please note that CFL lamps cannot be dimmed, unless they specifically state that they are designed for dimming.
Even if this is the case, they need a special kind of dimmer.
K8064: Hard to tell what happened. Most likely the triac is defective. This would be a good starting point.
Also check ZD1, T1, D1, R1, R2.