Yesterday i bought this kit. I carefully took the time to assemble it perfectly with the right components and nicely soldered contacts (took me about 2 hours!). After i was done, i connected it to 12V adaptor and the clap light stayed on. It doesn’t react when i clap or whatsoever. However, if i manually connect 2 contacts on the board, i hear the relay switch and the relay led goes on. I am sure i did everything right, but for 1 diode, and while trying to disconnect it, i broke it Damn, i really wanted this to work. The red light still stays on when i connect it however
I read on other forums 3 cases of people having the same problem with the clap light and not responding to any sound. Is this a defect in the kit, or is there a known sollution for it?
There is no problem with the kit.
A stunning 90% of all returned kits feature an assembly problem, so that is where you should start looking. Check all solder joints for bad solder joints, forgotten solder joints, touching solder joints, etc… Check all polarized components (leds, diodes, capacitors,…) for correct direction. Make sure all resistor values are correct. Check your pcb tracks and pads for damage due to excessive heat. Make sure LM324 is inserted correctly. Check all voltages (5V, 8V and 12V). Make sure they are present (see diagram). Make sure Gnd of microphone is properly soldered. If you cannot solve the problem, return kit for inspection.
I checked everything more than 10 times. No solder joints are touching eachother and all are firm and nice small flat bumps. Before i started i carefully sorted out all components, especially the resistors which are the most difficult to distinct. After that, i took the time to check polarity of each component and soldered them according to the instructions. Also the IC notches are on the right side according to the manual.
The only this which i found was very stange was that the polarity of the microphone was reverse drawn in the manual! It has 2 pins and a small flat piece of metal. If you check the + printed on the board and the + in the manual, you can see these are on the opposite side (on one, it is on the side with the flat metal piece and the other says it’s the other pin). However, there is a notch in the board for the piece of metal, so i only could insert it 1 way in contrary of the manual.
Can this be a problem?
Also, can i find a scan of the board front and back somewhere so i can recheck everything? Since all is soldered on it, i cannot see the lines and text on the board anymore.
You are correct, there is a small printing error in the manual. The large flat pin and the small pin next to it are the GND. However, the PCB is correct and the microphone cannot be inserted the wrong way round.
You can find the silkscreen here: http://www.velleman.be/images/tmp/MK139_silk.jpg
The component below IC2 (ZD1) got broken while trying to reverse it. Nevertheless the print appears to do the same thing.
This is the bottom. It was more neatly soldered, but with my expirimenting and loosening components it looks a bit nastier
At the red arrow, i soldered the joints together because i tought in the print they were connected. Is this correct, or should i disconnect them? I connected them, because the metal inside the print let loose on one of the joint while trying to remove a wrong solder :oops:
My first guess would be the reason your circuit is not working is because of the IC. I’m not familiar with the kit, but that looks like a logic chip or maybe even a comparator, hard to tell from the picture.
Nonetheless, chips aren’t exactly things that we can just glue back together. I’ve had chips stop working on me because I had applied a little to much heat while soldering; so a broken chip would defiantly stop working.
Other then that, you might have a solder bridge between pins 11 and 12. (At the very least it looks to be that way in the picture.) Should that be the case, take some solder wick or a sucker and clean all of the solder out, and reapply. Don’t try to just heat up the solder and move it around.
But as a disclaimer, I am not a certified electrician, yet. However, I’m 2 years into Electrical Engineering Tech. I hope something I’ve said here will help ya. =D
Hmm maybe there is something with the IC, because when i turn the power on, and leave the IC out, the light still stays on. Looks like it’s doing nothing, or not working correctly?
Do you mean pins 11 and 12 of the IC? That is some white dust or something i got on the board while soldering. I whiped of most of it, except there.
Componenten orientation and values look OK.
Sure you did not swap VR1 and VR2 ?
Don’t be offended, but the soldering looks rather poor. Check lower left hand side for shorts between solderings and also between R17 and R12
LOL, i’m a total amateur when it comes to soldering, so am really not offended But anyway i really did my best, and for my skills i tought i did pretty well?
Anyway, i double checked all components, and am really sure i swapped nothing, except for those transparent things (the one i broke ie), because they are very hard to distinguish.
I’ll check for shorts tonight and resolder the connections.
Also, please give me an advise why you think the solder is not good? What am i doing wrong? Also, what i did at the red arrow, can it do any harm?
Please check kit soldering hints. Basically, you need to heat both pcb pad and component lead and apply solder until you get a nice cone-shaped joint. Practice makes perfect. The area indicated with a red arrow looks very suspicious, however, it is impossible to tell if there is a problem there. At this point, if you are unable to solve the problem yourself, you can return your kit for inspection.
Hmm last night i resoldered every contact and now the clap led stays off, but also when i clap The relay switch mechanism still works, also the relay led turns on, but the clap mechanism seems to be totally broken
I’m not sure how up to this you would be, but if you could find a data sheet on your IC and then use a multi meter to check it, that would be what I’d do.
Basicly a chip is does nothing more then look at signals coming into it and then based on that information, sends something back out. So once you find the data sheet for the chip, you should be able to see, i.e., that if pin 2 or 3 gets a signal, that signal is sent out of pin 4… or something like that.
Really, this is my favorite part of kit building, not having it work and then trying everything possible to get it working.
Oh, and when I was talking about the chip, I was talking about the actual pin legs as if you were to count up from pin 1, counter clockwise, starting at the dot on the chip. It looks like you might have a solder bridge there (this was on the bigger chip) which would also cause problems.
And a note or two on soldering. Try to put the soldering iron tip in such a way that it is making contact with the metal ring around the component hole and the component lead itself. On resistors you really don’t have to worry to much about overheating them. So if you have a handful of resistors and a blank board, you should be able practice soldering with little worry of destroying anything (I know, where is the fun in that?) But once you heat the component lead and the metal hole, and apply the solder, you should see that the solder flows right into place.
Keep us updated, I’m looking forward to your “it works” post.
Wow first of all, thank you for taking the time to help me with the problem, i really appreciate it
Second, yesterday i discovered i was soldering the wrong way I used to put solder on the soldering iron and then try to put it on the component and metal ring. In the faq i read, you need to heat the component and the ring without solder, and then hold the solder against the ring and component untill it fills up nicely. This is what i will try next time to get the perfect solder
I’ll go measure around tonight to check the voltages and connections. The IC check will be difficult, but i’ll try Only thing that sucks is that i broke that one diode below the IC, and i think the thing will never work unless i get a new one. But nearby there is no store which sell them, so i need to make some time free to get it a few cities away. Or can i simply put a wire to connect these points as a “temporary” sollution?
Multiple contacts seem to do it, but most easy to point out are the two on the left next to the large IC (see bottom view i posted). Not sure if it were the lower or the upper however, see and try