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Velleman K7200 or simular

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www.velleman.be/downloads/0/manual_k7200.pdf

wizpic said:
Hi guys and girls

Sorry for the delay on this, just found teh time to sit and scan the article
it is the full version of the Velleman kit 0-30v 0-10amps the only thing i have not got is a pcb layout for it. but i have included a pcb overlay which will give you some idea for teh layout i am in the proccess of re-designing pcb in P*otel has i want to make a dual psu with a PIC volt/amp meter

Have Fun

Cheers

wizpic
Click to expand...

Dearfriend

Did you got all the sourcecodes for all Vellman projects?

Please let me know!!!!!!!!!!!!!!!!!!!!
 

velleman.pdf

Not usre what you mean there
but uf you mean for there pic projects then no because velleman don's issue code just pre-programmed chip

i had file from years ago

wizpic
 

0-30v 0-5a+shema

wizpic said:
Not usre what you mean there
but uf you mean for there pic projects then no because velleman don's issue code just pre-programmed chip

i had file from years ago

wizpic
Click to expand...

Thanks, for your help

on the other hand, did you got the hex file for GTPUSB+ programmer?
 

velleman k7200 repair

:D:D Thanks Gevv ....
 

velleman download pcb

Here you go people her is my vesrion that i was working on

it is fully tested and working pcb enjoy

wizpic
 
k7200 r37-r40 velleman

Great!!
 

sprintlayout 5.0 manual

anyone cant tell me the size of the nichrome resistance wire (R37-40) it is a 16-18-20-22-24 awg wire:?:
 
mk3980 digital

Hi wizzz
I just used some 0.1R resistors and it works great

the bigger the wire you use more resistance you will have, just try some i think i used 24swg when the correct wire burnt out, but when i designed my own pcb for it i did it the way i did because i found over a period of time and long use the wire statrs to deacy and you get dry joints and the it just blows up

well that is what i found with vellemans way hope this helps

wizpic
 

www.valleman.com.br

Thanks a lot wizpic, well i cant use resistor 0.1 ohm 1-2-5-10 watt and that ok
 

pass:gevv

i use 10W as they can be fixed to heatsink but you could use 5W

cheers

wizpic
 

uoguelph.antoon

Hi everyone,

I've made this PSU and use the PCB of Gevv.
But I meet a problem when I start to calibrate the PSU. I follow the K7200 manual. I have connected an ammeter to the output, placed the potentiometers in the positions indicated.
But when I turned RV1 for the maximum current limit, R31 blowed up. It seems that there is a lot of heat. The voltage adjust it's ok. All the wiring are rights. I can't find the problem.
I've tried to disconnect the transistors PCB. But, when I move RV1, R31 blow up too.

I use 2 LM723CN,1 UA741, T3 is a BD902 (I didn't find BD646). For the current limit resistors I've tried different value, 5W and 10W type. But the same thing appears.

Can anyone help me to resolve this ?
 

pcb mk3965

Hi,

I think my problem went to the current limit resistors R37 to R40. I've tried different value. With high value, the heating of R31 is less high.
Does anyone know exactly the value for these resistors or have a formula to calculate ?

Thank yo for all the help.
 

velleman k7200 power supply kit

Hi gaga2410.


Read the entire topic and you see to use 0.1 ohm 10W resistors for R37 to R40 like wizpic used !!

It works great.


Regards.


jackrs:D
 

velleman psu k7200

Thanks Jacksr,

I will try this and let you know ! :D
I've used one 0.1ohm/25W because someone tell me it is ok, but it's not ok. :?
 

0-30v 5a ÅŸema

Hi everyone,

Wizpic you have done great. Can u advise about IC3 vk7200. I cant find the datasheet. What is the substitute?

Thanks
 

velleman k7200 0-30v

Yeah VK7200 is just vellemans code they are just standard LM723 IC's 2 of them one for voltage control and the other current

wizpic
 

www.a-and-tlabs.com

Thanks a lot
 

mk3965

Hi, I have completed this power supply, it looks like that it works fine. However, I could not understand one point: when I connected a load to the outs, I could not get a variable voltage after setting the current limiter in some ampere. I mean, for example when I set the current limiter to 4A, I have only 15V in the outputs. Netiher more , nor less then this value, because when ı try to decrease the voltage to a value less then 15V , it's ok that current also decreases from 4A, but when I try to increase the value above 15V, then current limiter is activated and closes the circuit. I ask that isn't it possible to switch the voltage between 0-30V when the current is set any value. (if ohm law is the authority here, then there is not much thing to do for the point I think ;). )
 

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