Surf PI buzzer (Silverdog)

[Al 2014]

Hi All,

Quick question for you knowledgeable people, I have built the PCB for the surf PI 1.2 from Silverdog and am struggling with what to expect from the circuit once complete (for tuning). I have made a reasonably quick makeup of a coil, but when plugged in nothing happened. I have zero'd the offset etc (followed the instructions) and think everything is correct. My main issue is with the buzzer, at first it would give a constant beep but is intermittent with movement it beeps whether the coil is attached or not - is this normal?

I think the issue may be with the buzzer and thought about replacing it but wasn't sure on what voltage buzzer I need to get as the HXD one I have isn't marked.

The coil I have made is the basic make a circle with nails on some ply and wrap it round nice an tight, I'm thinking of making a new Tesoro style coil but need to make sure my circuit is working first. I know that hooking it up to an oscilloscope would be best but I do not have one available for the next couple of weeks.

[bmwbiker]

You have taken the coil off the nails, haven't you . . . ?

As for the buzzer, I think piezo devices are fairly tolerant of voltage, but why not wire a headphone socket instead of the buzzer and plug some known good headphones in?

[Al 2014]

Yes the coil is off the nails and tightly wrapped in electricians tape.

i was planning on the headphone socket once I got it working but now you've mentioned it maybe I can attach the socket and attach the buzzer to a headphone jack just to test it with?

the reason I asked about the buzzer is:
1. It beeps (constant tone) regardless of if the coil is attached, is this normal
2. If I touch or wiggle (v gently) the buzzer it will start to buzz, so I thought maybe the buzzer is dodgy

ive read a few threads on dodgy buzzers n most of the tie it turned out to be the soldering, I've tried a couple of different things n the outcome is the same.

thanks

[bmwbiker]

Had to ask about the coil - you never know . . .

If the buzzer makes sound at any point there's probably nothing wrong with it. It's doing what buzzers do. The fact that it buzzes constantly is worrying - check that all the components on the board are soldered properly with no dry joints, no solder bridges, all polarity-sensitive devices are the right way round before you start looking at anything else.

I've never built a Surf, my Barracuda from Silverdog puzzled me for a while until I saw a question (either here or on THing) where one would work on 12V but not on 9V. Since mine came with a PP3 battery clip I had used that but as soon as I put 12V into it it works fine. Luckily, apart from that mine worked right off so I've never had to do any fault-finding.

Hopefully somebody who knows more will be along soon . . .

Good luck

[Al 2014]

Ha I know, worth asking. some of things I've read makes you wonder....

Thanks for your thoughts, I'll will double check my components and welding fingers crossed I find something.