On 23/05/2010 12:12 PM, Orchid XP v8 wrote:
>>> And then I walked back into the shop and bought some batteries. Because,

>>> batteries is pretty much a normal price really.
>>
>> The next thing you should build is a dual voltage power supply.
>
> Uh, why?
>
> 1. If I actually wanted one, I could *buy* one for a very modest price.
> (And that way, it would actually work properly.)
>

Why not? It is educational, useful, fun and profesional. You will often 
use one supply (5V for TTL Vcc) and another for a signal or maybe a 
relay supply.

> 2. I don't know how many amp-hours an AA battery is, but with each IC
> using several micro-watts of power, I don't envisage running them flat
> any time soon.
>

But you will sometime and there is always the chance of you not noticing 
the battery voltage dropping and your circuts not working properly.
But then I only worked in electronics for 25 years so what do I know ;-)


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Best Regards,
	Stephen

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On 23/05/2010 12:10 PM, Orchid XP v8 wrote:
> Well, I don't know where my soldering iron, solder or wire cutters are.
> And I know from experience that trying to strip wires is approximately
> impossible, and trying to tin the ends is very tricky.

Using propper snips gently compress the insulation,about a 1/4 to 3/8 of 
an inch (6 to 10 mm) rotate the snips 90 degrees left then right. 
Release the wire and grip it again where you first gripped it with the 
snips and pull. Alternatively using a sharp knife, score the insulation 
to the wire all round the wire and pull the insulation off with your 
fingernails or teeth.
To tin stranded wire twist the strands so that none are sticking out. 
Have either a loop of multicore solder sitting on your bench with a 
couple of inches sticking up or your spool of solder with some solder 
sticking up. Tin the iron with solder so that there is a drip on the 
iron and tin a little bit of the wire. Take the wire to the top of the 
solder and with the iron, gently melt the solder whilst drawing the wire 
through the melted solder.
It is harder to write it than to do it. :-)


-- 

Best Regards,
	Stephen

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>>> The next thing you should build is a dual voltage power supply.
>>
>> Uh, why?
>>
>> 1. If I actually wanted one, I could *buy* one for a very modest price.
>> (And that way, it would actually work properly.)
>
> 
> Why not?

Because when it doesn't work, I will probably end up killing myself, for 
starters... A power supply is far too complicated for me to get right.

>> 2. I don't know how many amp-hours an AA battery is, but with each IC
>> using several micro-watts of power, I don't envisage running them flat
>> any time soon.
> 
> But you will sometime and there is always the chance of you not noticing 
> the battery voltage dropping and your circuts not working properly.

Oh, I'm sure they'll do that anyway. ;-)

> But then I only worked in electronics for 25 years so what do I know ;-)

Heh, where to buy capacitors cheap, I imagine. ;-)

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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>> Well, I don't know where my soldering iron, solder or wire cutters are.
>> And I know from experience that trying to strip wires is approximately
>> impossible, and trying to tin the ends is very tricky.
> 
> Using propper snips gently compress the insulation,about a 1/4 to 3/8 of 
> an inch (6 to 10 mm) rotate the snips 90 degrees left then right. 
> Release the wire and grip it again where you first gripped it with the 
> snips and pull. Alternatively using a sharp knife, score the insulation 
> to the wire all round the wire and pull the insulation off with your 
> fingernails or teeth.

With the thickness of wire I'm using, 6 mm would be several times the 
total diammeter of the wire. ;-)

> To tin stranded wire twist the strands so that none are sticking out. 

Oddly, this is significantly harder than you'd think...

> Have either a loop of multicore solder sitting on your bench with a 
> couple of inches sticking up or your spool of solder with some solder 
> sticking up. Tin the iron with solder so that there is a drip on the 
> iron and tin a little bit of the wire. Take the wire to the top of the 
> solder and with the iron, gently melt the solder whilst drawing the wire 
> through the melted solder.
> It is harder to write it than to do it. :-)

The 30-year-old solder I found seems to be quite "bubbly", which makes 
it difficult to do this. It also doesn't seem to want to melt very 
evenly, resulting on lots of blobs, or only one side of the wire tinned.

Now I remember why I wanted to buy wire ready-cut. ;-)

Still, I have just spent about an hour sitting on my driveway with a 
workmate, several bunches of wire and a soldering iron. People probably 
think I'm weird now... Everybody's out mowing the lawn, riding bicycles, 
having a BBQ or sunbathing, and some sad tosser over at number 11 is 
sitting with a bunch of wires and tools.

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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On 23/05/2010 3:24 PM, Orchid XP v8 wrote:
>> But then I only worked in electronics for 25 years so what do I know ;-)
>
> Heh, where to buy capacitors cheap, I imagine. ;-)

Buy? ROTFL

-- 

Best Regards,
	Stephen

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>>> But then I only worked in electronics for 25 years so what do I know ;-)
>>
>> Heh, where to buy capacitors cheap, I imagine. ;-)
> 
> Buy? ROTFL

Let me guess... REAL engineers MAKE capacitors out of foil and wrapping 
paper? :-P

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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On 23/05/2010 3:29 PM, Orchid XP v8 wrote:
>
> With the thickness of wire I'm using, 6 mm would be several times the
> total diammeter of the wire. ;-)
>

So, you can always trim it.
You might be better using solid core wire if it is that thin.

These sort of things are learned by experience and listening to the old 
men round the camp fire
.
.
>> To tin stranded wire twist the strands so that none are sticking out.
>
> Oddly, this is significantly harder than you'd think...
>

I know, strip and tin one end first then strip the other end. That stops 
the strands getting mangled.

>
> The 30-year-old solder I found seems to be quite "bubbly", which makes
> it difficult to do this. It also doesn't seem to want to melt very
> evenly, resulting on lots of blobs, or only one side of the wire tinned.
>

Tin the end first then when the strands can't separate do the length. 
Use a dry iron to stroke the blobs off.

BTW modern solder has better flux.

> Now I remember why I wanted to buy wire ready-cut. ;-)
>

LOL

> Still, I have just spent about an hour sitting on my driveway with a
> workmate, several bunches of wire and a soldering iron. People probably
> think I'm weird now... Everybody's out mowing the lawn, riding bicycles,
> having a BBQ or sunbathing, and some sad tosser over at number 11 is
> sitting with a bunch of wires and tools.

Good job they can't see you with PovRay ;-)

-- 

Best Regards,
	Stephen

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On 23/05/2010 3:42 PM, Orchid XP v8 wrote:
>>>> But then I only worked in electronics for 25 years so what do I know
>>>> ;-)
>>>
>>> Heh, where to buy capacitors cheap, I imagine. ;-)
>>
>> Buy? ROTFL
>
> Let me guess... REAL engineers MAKE capacitors out of foil and wrapping
> paper? :-P
>

LOL, They get them from work ;-)

-- 

Best Regards,
	Stephen

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>> Let me guess... REAL engineers MAKE capacitors out of foil and wrapping
>> paper? :-P
> 
> LOL, They get them from work ;-)

There are people who get paid money to do stuff involving capacitors? o_O

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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On 23/05/2010 4:10 PM, Orchid XP v8 wrote:
>>> Let me guess... REAL engineers MAKE capacitors out of foil and wrapping
>>> paper? :-P
>>
>> LOL, They get them from work ;-)
>
> There are people who get paid money to do stuff involving capacitors? o_O
>

:-D

-- 

Best Regards,
	Stephen

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