Prev: I?ll write probability of total extermination in the period of future month. According to their plan, the first 2*3.5TeV collisions will be performed the 30-th of March.
Next: The first 2*3.5TeV collisions will be performed the 30-th of March. CERN's plan of Earth explosion.
From: Bob Masta on 16 Mar 2010 10:53
On Tue, 16 Mar 2010 13:23:14 +0200, Kari Laine
<klaine8(a)gmail.com> wrote:

>Hi,
>
>I am total beginner with electronics....
>
>I am learning this Daqarta scope program (www.daqarta) and at the moment
> I am wondering the power output of function generator. I am planning
>to buy (when I have the money) two velleman applifiers K4004B -
>http://www.velleman.eu/distributor/products/view/?id=352782
>I will configure them for mono.
>
>That should give me enough power. Problem is that manual says the
>outputs should be connected before power is applied. When testing things
>it is quite possible that I forget this. And it is quite possible I will
>short them for prolonged time. Velleman says that there is protection of
>10s for shorts - that is not enough.
>
>Any way to solve these problems?

Kari:

You don't mention what you intend to use the
amplified function generator outputs for... that
might make a big difference in recommendations.

The best and cheapest amplifier will probably be a
home-stereo amp (or the amp part of a receiver).
You may already have one on hand, or pick up an
older model (cheap or free) from someone who is
upgrading. The Velleman kit is 50 watts/channel
into 4 ohms or 40 into 8 ohms (real watts, not
"music power") which are fairly common home stereo
specs.

Note that sound card outputs are AC-coupled, just
like stereo amps (including the Velleman, I
suspect, since they don't claim otherwise), so you
will not be driving any DC loads.

It's possible to modify a cheap sound card to have
DC outputs, and it's fairly easy to modify most
stereo amps to have DC outputs, but these are not
good projects for beginners since it is too easy
to "let the magic smoke out."

If you are just in the process of setting up a
general purpose home lab, I'd advise against any
external amplifier for the function generator
until you have a specific need. You may discover
you don't need anything more than the sound card
puts out already.

Sound cards are usually well protected against
output load problems, and in fact handle (or at
least tolerate) low-impedance headphones. The raw
output is likely all you need to drive most test
situations, like frequency response and distortion
measurements.

Best regards,


Bob Masta

DAQARTA v5.10
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, Sound Level Meter
Frequency Counter, FREE Signal Generator
Pitch Track, Pitch-to-MIDI
DaqMusic - FREE MUSIC, Forever!
(Some assembly required)
Science (and fun!) with your sound card!
From: Kari Laine on 16 Mar 2010 13:18
John Fields wrote:
> On Tue, 16 Mar 2010 13:23:14 +0200, Kari Laine <klaine8(a)gmail.com>
> wrote:
>
>
> ---
> I suspect a couple of hits to the pocketbook will shorten the learning
> curve and lengthen the attention span appreciably.
> ---
What you mean with this...Do you mean I should buy some books or
something? If so ISBN is?
My attention span is very bad indeed, it has always been. Nowadays they
even have a diagnosis for it...

>
>> Then I would need a power supply for +/- 28 DC for these amplifiers.
>> It is not clear to me what the maximum amperage should be - anyone?
>
> ---
> According to the specifications, 4 amperes.
Thanks did not notice it.

Best Regards
Kari

From: Kari Laine on 16 Mar 2010 13:29
Bob Masta wrote:
> On Tue, 16 Mar 2010 13:23:14 +0200, Kari Laine
> <klaine8(a)gmail.com> wrote:
>
> You don't mention what you intend to use the
> amplified function generator outputs for... that
> might make a big difference in recommendations.
Well...main reasons - it would be "cool".
I though that it would open possibilities to test different things.
- solenoids
- transformers
- inductors
- PWM

and so ... mainly I am just curious.
But like you say I might not even need it.

>
> The best and cheapest amplifier will probably be a
> home-stereo amp (or the amp part of a receiver).
> You may already have one on hand, or pick up an
> older model (cheap or free) from someone who is
> upgrading. The Velleman kit is 50 watts/channel
> into 4 ohms or 40 into 8 ohms (real watts, not
> "music power") which are fairly common home stereo
> specs.
This is a good idea - I try to find used amplifier which I don't mind
destroying.

>
> Note that sound card outputs are AC-coupled, just
> like stereo amps (including the Velleman, I
> suspect, since they don't claim otherwise), so you
> will not be driving any DC loads.
Ok

>
> It's possible to modify a cheap sound card to have
> DC outputs, and it's fairly easy to modify most
> stereo amps to have DC outputs, but these are not
> good projects for beginners since it is too easy
> to "let the magic smoke out."
Ok - I won't try it yet.

>
> If you are just in the process of setting up a
> general purpose home lab, I'd advise against any
> external amplifier for the function generator
> until you have a specific need. You may discover
> you don't need anything more than the sound card
> puts out already.
I put it in the back burner - the Velleman that is.
One other helpful person gave two links and I am going to spend some
days reading those - very good sites!

>
> Sound cards are usually well protected against
> output load problems, and in fact handle (or at
> least tolerate) low-impedance headphones. The raw
> output is likely all you need to drive most test
> situations, like frequency response and distortion
> measurements.
OK

Now when I have you attention you hopefully don't mind a question.

How to find out capacitance and inductance with using function generator
and scope? Is it easy,not so easy, hard, very hard or impossible?
I remember seeing this somewhere in the net, but don't find it now.


Best Regards
Kari


> Bob Masta
>
> DAQARTA v5.10
> Data AcQuisition And Real-Time Analysis
> www.daqarta.com
> Scope, Spectrum, Spectrogram, Sound Level Meter
> Frequency Counter, FREE Signal Generator
> Pitch Track, Pitch-to-MIDI
> DaqMusic - FREE MUSIC, Forever!
> (Some assembly required)
> Science (and fun!) with your sound card!


--
PIC - ARM - DISPLAYS - RELAYS - MODULES - CONVERTERS - I2C - SPI -
KEYPADS - ACCESSORIES
http://www.byvac.com (I am just a satisfied customer)
From: John Fields on 16 Mar 2010 12:56
On Tue, 16 Mar 2010 19:18:50 +0200, Kari Laine <klaine8(a)gmail.com>
wrote:

>John Fields wrote:
>> On Tue, 16 Mar 2010 13:23:14 +0200, Kari Laine <klaine8(a)gmail.com>
>> wrote:
>>
>>
>> ---
>> I suspect a couple of hits to the pocketbook will shorten the learning
>> curve and lengthen the attention span appreciably.
>> ---
>What you mean with this...Do you mean I should buy some books or
>something?

---
No, just a tongue-in-cheek way of saying that if you spend enough money
on being careless with amplifiers you'll eventually probably discipline
yourself so that it doesn't happen. ;)
---

>My attention span is very bad indeed, it has always been. Nowadays they
>even have a diagnosis for it...

---
"Attention deficit disorder" or something like that?

Be very careful working around electricity if your mind has a tendency
to drift; it's easy to hurt or kill yourself and the equipment you're
working with if you lose track of what you're doing. :-(
---


>>> Then I would need a power supply for +/- 28 DC for these amplifiers.
>>> It is not clear to me what the maximum amperage should be - anyone?
>>
>> ---
>> According to the specifications, 4 amperes.
>Thanks did not notice it.

---
You're welcome.

JF
From: Michael Black on 16 Mar 2010 13:26
On Tue, 16 Mar 2010, Kari Laine wrote:

> John Fields wrote:
>> On Tue, 16 Mar 2010 13:23:14 +0200, Kari Laine <klaine8(a)gmail.com>
>> wrote:
>>
>>
>> ---
>> I suspect a couple of hits to the pocketbook will shorten the learning
>> curve and lengthen the attention span appreciably.
>> ---
> What you mean with this...Do you mean I should buy some books or
> something? If so ISBN is?

I had an analog meter when I was 12, and soon it no longer worked, the
needle having wrapped around the stop too hard. I was careful of any
later meters, having learned the lesson.

Or, that time when I touched high voltage and when I pulled away my elbow
slammed into a hard surface enough to hurt, I was careful of high voltage
after that.

In other words, actually doing mild damage may be a better way of
preventing accidents than merely warning someone to not do something
because it might cause an accident.
Michael


> My attention span is very bad indeed, it has always been. Nowadays they
> even have a diagnosis for it...
>

>>
>>> Then I would need a power supply for +/- 28 DC for these amplifiers.
>>> It is not clear to me what the maximum amperage should be - anyone?
>>
>> ---
>> According to the specifications, 4 amperes.
> Thanks did not notice it.
>
> Best Regards
> Kari
>
>
First  |  Prev  |  Next  |  Last
Pages: 1 2 3 4 5
Prev: I?ll write probability of total extermination in the period of future month. According to their plan, the first 2*3.5TeV collisions will be performed the 30-th of March.
Next: The first 2*3.5TeV collisions will be performed the 30-th of March. CERN's plan of Earth explosion.