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Author Topic: LFO mod help  (Read 7016 times)

tilde

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LFO mod help
« on: January 01, 2013, 04:42:59 PM »

Hi

I'm attempting to build the LFO mod as illustrated at casperelectronics (http://casperelectronics.com/finished-pieces/speak-n-spell/speakspell-bending/).

The toy that I am using is only powered by 3v (2x AA) battery which does not seem sufficient to power the LFO. Can anyone suggest what modifications I need to make in order to make it compatible  -  changing capacitors, resistors etc?

It's my first attempt at building one of these so please excuse me if I'm missing something obvious.

Thanks
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Circuitbenders

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Re: LFO mod help
« Reply #1 on: January 01, 2013, 10:39:47 PM »

it depends what 555 you're using, but the minimum supply voltage of most 555's is around 4.5v.

I doubt it'd work on 3v no matter what changes you made.
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tilde

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Re: LFO mod help
« Reply #2 on: January 02, 2013, 10:02:53 PM »

Thanks for the reply

I didn't know there were different flavours of 555.  I've now ordered some TS555CN low power versions and will try them out tomorrow.

Learning new stuff everyday!
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Circuitbenders

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Re: LFO mod help
« Reply #3 on: January 03, 2013, 09:19:20 AM »

I suspect that even with a low power CMOS version, you'll probably have an issue with not being able to get a very wide sweep using a 3v supply. It can't give you a pulse at a higher voltage than the supply voltage and the output current it can deliver is virtually nothing.
http://www.talkingelectronics.com/projects/50%20-%20555%20Circuits/50%20-%20555%20Circuits.html#G1

You might as well give it a go though.  :-\

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tilde

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Re: LFO mod help
« Reply #4 on: January 04, 2013, 03:43:37 AM »

Wow a 555 bible - fantastic resource!
I'll give it a try and get back to you folks  :)
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