Hello,
I purchased one MK 139 kit, and after assembling it i sadly discovered that it doesn’t work. The “clap” led is blinking as i clap but the relay doesn’t closes.
Any ideas?
My biggest concern is that the pic being damaged because when i got home i realised that the cip had fallen from the conductive sponge, inside the plastic case.
Thanks in advance.Back with updates…
Today, when i plugged in my power source into the MK 139 the relay led went on for a couple of seconds and then he slowly (maybe 10 seconds) shut off. When i clapped my hands, surprise, it worked fine.
But after installing properly for my living lamp the problem occured again. No triggering…
What should i do?
Thanks in advance.
Most likely a mechanical problem such as bad, loose or forgotten soldering etc…
I checked the pcb twice… It must be a really hidden loose connection…
Are there any known issues or more frequent ones with theese kits?
It worked before, you then manipulated it to connect it to your lightbulb. Something must have happened or something must have changed.
Electronics do not go bad overnight 
I tought that the pic’s software malfunctioned due to repeated connection/disconnection to/from the power supply. Now it works, again 
…
Let’s hope it will still do after installing in the wall socket.
Also i have a question: on the pcb it states 12V 150 mA, but after measuring it it consumes in st-by about 20 mA & with relay on about 60-70 mA, but me meter is a very low cost one. An 125 mA power supply will suffice (i want to build a separate power supply using a very small pcb transformer and a mini rectifier bridge so that will fit into the wall socket)?
Thanks in advance.
Your measurement is correct. 150mA is with safety margin included. Make sure your power supply is well filtered (i.e. use a large smoothing cap.).
Hi. I also have the same problem. The clapping indicator blinks when i clap but the relay led is always black. Does the kit need a load to function properly or should it work even without load? In my head I think that when the clap is indicated, it just make a bridge (with the help of the rele) and the Relay light should light to indicate it’s “working”.
Another question is if I have a problem with my kit, (the rele looks very dead for me, no clicking or so) where could I but a new kit. This kit I bougt from a reseller in Sweden that dosn’t sell this anymore. (kjell o company)
Best regards
Anders Johansson
The kit does not need a load to function properly.
Is the kit receiving 12VDC? (less is not OK. Also, make sure to use a good quality adaptor).
You can test the relay by removing the PIC and connecting pin 1 to pin 7. The relay should energize.
If not, check the transistor and/or desolder the relay. Test relay by feeding 12VDC to the two outer pins at the 3-pin side.
If the relay works, then either there is an assembly error in the analog section, the pic is not working correctly or the clap sequence is not correct.
Hi. The adapter shows 12,3 V. The same when it’s connected to the board.
I removed the PIC and connected 1 to pin 7 with no result. I mesuared the voltage on pin 1 and 7 and both shows 5 V. Then I unsoldered the Realy and connected 12 V directly and that is workin fine. I can hear it switch. Should I realy measuare 5V on both pin 1 and 7?
/AJ
If you measure 5V at pin 7, replace relay drive transistor and check if relay suppressor diode is correctly mounted. If any doubt, replace.
After some more investigation I solved the problem by resolder one of the condensators. Now everything works like a charm My bedrom roof light is now controlled by clapping:) Thaks for great and fast support.
/AJ