Aspect #08 07 апреля 1998

Железо

Iron - What is a "Tester" and what it eats.

 To work with the hardware needed
various measuring instruments.
Novices often shocking abundance
various scales and obonacheny. Help them
razobratsya in this miracle technology and is designed to
this article.



    WHAT IS testers, and what it eats.


          1. Why is it necessary.

 Imagine the situation: Collect shemku,
say, a blocker port # 1ffd.
 Collected, include the computer, but it is not
breathing, and shemka collected correctly and
All items rabochie. Aha, so the wire
"Flew". But which one? It is possible,
Of course, use this simple
technical devices, such as
Tear wires and soldering them on
place model (ie, about which
know that it working). But most likely
it ends burnt the board. And what
do? Smuggle an ohmmeter and measure the
resistance of conductors. Well, and if
will need to measure the DC voltage
the resistor, then we will make it through
DC voltmeter. A
supply voltage will be measured not by two
fingers, and AC voltmeter
voltage. Current in the circuit, respectively,
We measure the ammeter. And now
Imagine this: Are you going to shemku, but close
with you on the table ohmmeter, voltmeter
different, ammeter. Well if the table
great ... So in order not to
tortured to conduct the above described measurement
You can use just a tester, in
which combines all of these devices.


         2. The first acquaintance.

 Typically, the tester can detect
nests, which are inserted, no, not your fingers -
plugs measuring needles. About
plugs painted icons "+" and "-"
pokazyvyuschie polarity. Plus sign
depicted in red, and at the nest,
near which it stands, we must stick
Plug the red measuring needles, and there
where the minus sign - black. Furthermore, examining
building this device, you can see the scale of
with an arrow, and on it some
mysterious inscription. Usually, if
look closely, you will notice the switch,
with which you can choose the type of
dimension and its range. About the mysterious
potentiometer on the side of the tester, I do
default. A little more on the scale: usually
It is possible to find a silver stripe
which serves to improve the accuracy
measurements. To obtain the testimony
instrument to look at the arrow, so
so she closed her reflection.
By the way, if you look at the tester
back, you'll see a small screw. So, if
unscrew the screw and remove the cover, you can
find a place under the battery, in which
and must insert the correct polarity.


   3. DC voltage measurement.

 The switch should be put into the sector "DC
V "(which means" Jure voltage ").
Next, put a maximum limit
Measurements - tsiferki written in the sector
"DC V" (for example, if you have written there
2.5,10,50,250,1000 it is necessary to put 1,000
). Why so many? And who knows -
can you turn on the limit of 2.5 V, and the chain
will be 800 ... Then you can safely
throw away your tester. Further, the sticks
jacks, and a sadistic smile
connected in parallel circuit element, the
which are going to measure the voltage
(Voltmeter has high resistance, and if you consistently kerf,
then the current flowing through the chain will not). If
arrow tries to break through the wall
device you connected properly - both
Typically, sufficient to interchange
needles, and everything will be OK. Look carefully at the scale 
... Which one? And the one about which the left (or right) is 
written "AC DC" or "DC". Next, choose those

inscription around it, which correspond to
put to the limit of measurement. Ie
for 250 select 250 for 50 - 50, for
10 - 10 for 1000 - 10.20, or 250,
only need to be multiplied accordingly
at 100.20, or 4 to 2.5 V - 250, and testimony will be divided 
by 100. What to do if the arrow at 0? Necessary to change the 
limit of measurement: if it was 1000 - set 250, and so on. But 
if at 2.5 volts will also be 0, then it is 0, and go away

no escape. Yes, again: if you vzbredet
in the head to measure the voltage at the pulse
current (ie rectified), it will be
equal to the average value, not
max.


   4. Measurement of alternating voltages.

 To measure ac voltages necessary to put the switch in the 
sector "AC V", and then everything in the previous

paragraph, only the polarity no role
plays.


         5. Current measurement.

 Put the switch in the sector "DC A"
(Because we measure the DC).
Further, the method is the same as when measuring
constant stress, but AMMETER
Plug-in open circuit, ie Sequentially. If you do not follow 
this condition, the tester you will be heating, iron and 
toaster in one person ... In short, burn it. It also makes 
sense to clarify Strange inscription near the limits: 
grecheskoya the letter "Mu" means that the current is given in

microamperes, and the Latin "m" - in
milliamperes.


       6. Resistance measurement.

 The switch should be put in the position
"Omega", and plugs plug into the slots.
Then, close the two measuring pins,
and a potentiometer on the side of the tester
achieve zero position
direction (measured on a scale
about which it is written "OHMS", that
Russian stands for "Ohms". Having achieved this,
choose the limit of measurement by which
testimony or multiplied by 10, or immediately
considered in kiloomah. Next, we connect with
study findings resistor
measuring needles, and remember
testimony. Very handy with an ohmmeter
check the wires on the gap, because gap
has a resistance, while the wire
(Short), the resistance is zero. Well,
set the switch to "1K" and
connect the needle with the ends of the wires. If
resistance 0 - wire normal, well
if not 0, then all of them clearly.

 Well that's all I can say no
plunging into impassable jungle of the theory.


                           (C) Trusov Ilya.

P.S. There may be other designations:


             DC V-V


             AS DC or DC-V


             AC V ўV


             DC A A


                                 Editorial.