login
logitec
-
Posts
40 -
Joined
-
Last visited
Never
Content Type
Profiles
Forums
Events
Posts posted by logitec
-
-
well i dont think i could use any other scale but digital
and writing a program that i will be able to show the information in a graf i think it is hard spacialy when i have never programed any thing program-hard ware -
-
Hello .
Resently I have started geting interested in modifing a scale so I will be able to see a graf on my computer of any wight movements.
I saw here some when a thermometer that doing the same can I modify just the parts and use the same program? and as the sensor i will use a usual human scale?
tnx Ron
some thing like this one
http://www.electronics-lab.com/projects/pc/013/index.html -
Hi Ron,
I recommend this parts list for the project to work well and be reliable. A few months ago someone recommended adding trimpots in series with the controls for calibration.
hello agin
i have started building this project and i have left one capistor not in use where does it satnds?
C10 electrolitic 10UF
ron -
hello MP
I did some reading in this post and i saw a few people that had problems with this project
hello audio
can you tell me what difference and corrections those parts are making
i mean why have you changed these parts -
hello all
i see there are alot of mistakes in this project (almost 60 pages)
can any one tell me what i need to know to build it, problems and what was discussed
Ron -
TNX i didnt thought about it
-
Can't you buy resistors with 5% tolerance?
Is there only one reasistor value you can't find? Which one in the circuit?
yaa i can find the 0.47 Ohm with 10W (the only one i found with this resistens was 0.128W :S) -
-
ammm
what wre the pots and trimpots? -
I am sorry I missed your question before. In this thread we discuss problems with the original design for this project and fixes for them. The voltage and current of the original spec'd transformer were too small. Increasing the transformer's voltage means that special high voltage opamps must be used. See my recommended parts list.
People who built the original project reported that these little diodes get too hot. A 1000V 1N5408 diode will also get too hot. I recommend using a high-current rectifier bridge module bolted to a metal chassis.
A 1N752A zener diode is tested and designed to operate at 20mA. D8 is the project's main voltage reference and R4 in the original project supplies only 1.2mA to it. The 1N752A's datasheet shows that its voltage is low and it barely regulates at such a low current.
I recommend using a BZX79C5V6 zener diode for D8 that is tested and designed to operate at 5mA, and changing R4 for 5.6mA.
D7 can be nearly any 5.6V zener diode.
A 1N4001 is rated for 50V and a 1N4002 is 100V but cheaper. A 1N4007 is rated at 1000V and is more expensive. The output of this project is only 30V so any of them will work.
Most resistors today are 5%. See my list.
oooo
i just came from the store :'( any way can you tell me more about the changed parts why changing them and in what are they better?
and one thing more i can install a cooling system (2 computer fans, intake and outtake) that will help?
Ron
-
a fue more questions:
-can i use 1N5408 diode in the place of D1, D2, D3, D4 where in the circuit was writen to use the 1N5402,3,4 diode 2A - RAX GI837U
-what is the diode that is writen on it 1N 75 2A 227 and can i place it as D7, D8 = 5,6V Zener diode
-can i put 1N4007 diode instead of D11 = 1N4001 diode 1A
- how much Tolerance can i give to the R1 and to R7
Ron -
that isnt a problem
and what out put it has?
by the way i cant find this part at the main importer in the country so i dont think i can get it...
any other more common parts? -
OK
but steel i need some thing to hold the voltage and then regulate it
so what chip can i use that will not burn under 10A? -
the input voltage is 4V not 0.4V
and the out put3.6V
and i dont think that in my place so new components will be available to me
so lets go to the other way we can do this
transistor + resistor
but the voltage will be juppy after the transformer so i need another chip so lets say stablize to 4V from 5V
where can i get one like this?
and witch transistor and resistor i need? -
hello EdwardM
i actually meant a chip like 78L05 that stabelaizes 5V
of a circuit with exact parameters and tranzistors -
hello
can any one help me find stbilizator that will hold 10A and will be exact 3.6V
while his input will be 4V -
hello all
im searching for a circuit of a small triger the when a pin from my microcontrollor will set the first time high the output from this Circuit will be always high no matter if the input is 0 or 1 logical
opps i think it isnt the place for this massae sory
Ron -
how much watt i need for the transformator
??? -
hii all i am trying out this project:
http://www.electronics-lab.com/projects/pc/020/index.html
i have already prepered all the electronics to go(Im using the LPT port) but the program while i was trying to download it
its site was down
while the second program is only for COM ports...
can any one plz upload the first program to the site?
Ron -
hii
i have a question
82 Ohm
0.47 Ohm
1.5K
3.9K
for what they are used in this project and can i change those to some thing else more common resistors- even the shops dont have them is their stoke
and does it makes big difference if i put polyester condinsator instead of the ceramic ones?
Need help - Computerized Scale
in Electronic Projects Design/Ideas
Posted
the only problem is that im from israel and i dont have a place to buy it :-[
and about programing in vb , where can i get information about that?