RE: Re: Electronics Gurus brain required...

["Ian B" <Ian@xxxxxxx>]

For TR1 almost anything will do e.g. BC182. For TR2 I have seen
2N2222's
used for this. Check the current rating regards your planned current
usage.

For caps, most manufacturers do kits with a bit of everything in. I
bought
the electrolytic and ceramic ones from Rapid and have rarely had to
look
elsewhere for other values. Trial and error and a scope then for
optimum
results. Of course calculating the values would be good as well but I
don't
know how (yet).

Ian B

-----Original Message-----
From: andy_powell_is [mailto:ukha@xxxxxxx]
Sent: 28 May 2002 21:34
To: ukha_d@xxxxxxx
Subject: [ukha_d] Re: Electronics Gurus brain required...



Ian,

--- In ukha_d@y..., "Ian B" <Ian@M...> wrote:
> Spot on Andy. The tranny TR1 only needs to be small as there is no
current
> flow. TR2 however takes the full flow from up to x number of
emitters so
> needs to be suitably sized. It also needs to switch at a rate
suitable for
> IR transmission.

What sort of 'size' should I e looking at for TR1 and TR2? I don't
actually have any (still building up my component stockpile :) ) any
Ideas for makes and/or part numbers?? I've not used anything like
this before so any advice would help :)

> guess you could have lots o small caps at each diode take off or
one near
> the power supply that is larger. Trial and error here is good as
long as
> they are connected up correctly.

Are you talking pico farrads for the individual ones? or something
more substantial? And for the single one by the PSU.. again rough
guesses are fine as I can buy a few with different values...

>
> For testing purposes I would build the circuit up from the IR end
back
> towards HV testing each bit worked. If not you may end up with a
non working
> circuit and not the foggiest where it is going wrong.
>

Methinks that will happen anyway :P


> Hope this is helpful

very much, thanks Ian


>
> p.s. Babs arrived so my time is a little short at the moment and I
am
> knackered!! Mum and daughter doing well, no names decided on yet.

Congratulations! As for names - well Baby Paws has been taken :P

Andy




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