Problems adding buzzer to gotek

[Glen M]

I stumbled across a thread that shows a buzzer added to a gotek drive so I decided to try it myself. The picture on the thread shows it assembled as follows.

http://kipper2k.com/amiga/gotek/gotek.jpg

I've assembled mine the same but the buzzer sounds constantly. Any ideas what I've missed?

I've used a 5v buzzer, 1k resistor and bc547 transistor as per the instructions.

[Amiga1992]

Can you post a pic of what you have done?

[Glen M]

Sorry for the delay in posting, imgur was being strange.

Anyway, here is a picture of what I have done. The keen eyed will notice the resistor is actually 1.1k but it was all I had. I later swapped it out for 3x330 in series so 990ohm but this to made no difference, the buzzer just sounds constantly. I'll call to the electronics shop later and get a few 1k resistors but I doubt it'll make any difference.

http://imgur.com/geEI8BQ

[Allen1]

The problem could be that the transistor is damaged ie static or possibly heated for too long especially the lead with the black wire on it. If you have another transistor then try that, the resistors were/are close enough in value so it should have worked.

[Daedalus]

Yep, the problem isn't the resistor, for a transistor switching circuit, almost any value would work (within reason...) - though I'd have gone closer to 10K myself. Can you measure the voltage at each side of that resistor while it's running and tell us what you get?

Also, have you checked the transistor part number? Just in case you have the transistor's complement, the BC557, which would cause some funky behaviour.

[Glen M]

I tried 2 different transistors, only touched the solder for a second so I doubt heat damaged them both. The part number on the transistor is BC547B NPN transistor.

I'll look at measurements tonight if I get the chance. Will need the ear defenders out though as the buzzer is bloody loud, either that or a bit of tape over it will do!

[robinsonb5]

I'm not 100% sure but I think your problem here is that you're using a buzzer that has internal driver circuitry, rather than just a transducer.
Kipper used this part: https://www.digikey.co.uk/products/e...ds=668-1373-nd which doesn't have an internal driver, so it will only click when the level of the step signal changes.

The /STEP signal is active low, which means the transistor will be passing current while the disk drive is idle, which is why your buzzer is sounding constantly. You could add a second transistor to invert the /STEP signal, or just replace the buzzer with a driverless one.

[Daedalus]

Ah, of course! That's probably it alright! Good call robinsonb5 - I never really thought about what the buzzer was actually doing.

[supaduper]

Yes I`d agree most defo the buzzer
try these they work well
http://www.ebay.co.uk/itm/KINGSTATE-...item27f6a6f8b1

[Glen M]

Cheers guys. I thought a buzzer is just a buzzer but apparently not. I've ordered up that one in the link so hopefully that resolves the issue.

[liviux76]

Years ago I bought a few buzzer kits for my goteks from supaduper (really a great guy!) and they always worked perfectly! You will certainly solve your issue!