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Dual volt amp meter help with schematics

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SSShocked

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i need a dual volt and amp meter up to 300v 20a
does anybody know something
please help
 

Dear SSShocked
Hi
How much accuracy , do you need for your measurement ?
Best Wishes
Goldsmith
 
needed for power supply
recomended 10mV/A or 1mV/A accuracy
for output and set volt/amp monitoring
 

humm . is , cost important for you ? if no , why not , a hall effect sensor ? ( for current ) and for voltage , you can divide your out put voltage with some resistors , and then measure it simply ( with a microcontroller ) .
By the way , is isolation important for you ?
Best Wishes
Goldsmith
 
300v 20a max
cost not more than 60$
i need the schematics and code
i am not experienced with microcontrollers
i need a 20x4 LCD panel meter
that measures voltage and current
 

For current , you can use a low value resistor , that is in series with your line , too . but let me ask a question : have you access to the AC voltage ? my mean is : i think that you had an AC source and then you rectified it . if , yes , you can use a CT in your AC line before rectification . i think it will be cheaper and better for you .
Best Luck
Goldsmith
 
**broken link removed**
look at it
this is the best power supply (mc1466)
it is a transistor controller
line reg.0.02
volt.reg 0.03
voltage and current adjustable from 0 to X
the max. voltage and current depends on that
how powerfull is the output trasnsitor
if your transistor is 300v
you can regulate it from 0-300v
current limiting included
this is the block diagram of MC1466L
MC1466 is not produced anymore
the datasheet
http://www.datasheetcatalog.com/datasheets_pdf/M/C/1/4/MC1466L.shtml

so i need that meter for this PSU
 

It is kind of linear PSU , and i don't think it's efficiency is good , and naturally , it won't be economical ! consider your out put current is about 20 A and your out put voltage is 2 volts and your input is 300 volts ! so , your dissipation across your series pass element will be about 20*298 ! = 5960 W ! is this reasonable ? why not a simple buck converter ? if you need a good PSU , you can design a simple buck converter . it's efficiency can be very high !
Good luck
Goldsmith
 
you are right
but i will use it directly from the mains
so i will use a few 150W transistors
so max power will be 900w
0-250v 0-15a
60v at 15a
i dont need 6KW PSU
get it

---------- Post added at 14:37 ---------- Previous post was at 14:36 ----------

i will drive flyback transformers,tube amps and other things like that so 250v are enough
 

at 250v i should have around 3.6 amperes
also i think that oil cooling will dissapate
much more than 6000w

to dissapate those 900 watts i will put the transistors in a box filled with cooling liquid pumped trough a small radiator with VEEERY powerfull fan
the pump is VEEERY fast (150L/min)
it is super small and fast
the box will be air tight
so let's get back to the panel meter
 

However i don't think that 900 w dissipation is reasonable and economical ( because you can have just 10W dissipation with an SMPS ) , but as you wish . lets back to your original question : use a CT ( current transformer ) in series with your AC line to get sample from current . and for voltage : use a divider network ( with two high value resistor ) ( with 0 or 0.1 percent tolerance ) to get sample from your voltage . and then use a microcontroller ( It's ADC ) . or use a 7107 integrated circuit , what with that , you can design an ammeter and voltmeter . ( but if you use this method it will be a bit hard to use LCD ) ( so i think micro controller is more suitable )
Best Wishes
Goldsmith
 
dude i know how to connect the meter but i dont have the schematics of the display driver
get me
all on 20x4 LCD
i need the schematics to drive the display and the code for the MCU

---------- Post added at 14:51 ---------- Previous post was at 14:50 ----------

also how to achieve 0-250v 0-3.6a with SMPS

---------- Post added at 14:52 ---------- Previous post was at 14:51 ----------

and the noise of the SMPS
 

About noise of SMPS , if you design it's output filter correctly , you won't have any problem .
And about SMPS : you can use a buck converter , simply . two mosfet and an IR2113 and an LM2576 and an opto coupler and a filter at the out put ( or two filter ) and an op amp .
If you want , i can give you a schematic for this . and for current and voltage , indication on LCD , i'll find a suitable thing for you .
Best Wishes
Goldsmith
 
really?
3.6a at 250v
15a at 60v

---------- Post added at 15:01 ---------- Previous post was at 14:59 ----------

can you show me some

---------- Post added at 15:22 ---------- Previous post was at 15:01 ----------

another problem:
reliability they explode when they want
 

Ok , but , do you need two independent circuit first one for 60 volts and the other for 250 volts ?
Yes , i'll draw it's circuit for you soon .

another problem:
reliability they explode when they want
Click to expand...
What do you mean by that ?
 
i mean:
short circuit=BANG!
high load for long time=BANG!
also they have pretty bad regulation and load response

but they are cheaper so
i need a PSU that is 900w max->0-250v 0-15a
i mean 15a at 60v 3.6a at 250v
get it
900w max
0-250v 0-15a
ADJUSTABLE
 

Why bang !! :-D ? duty of protection , is avoid from bang !!!!!! ( but at high power SMPS systems , if your circuit hasn't any protection , you won't see bang ! you'll see big bang !!!!!! ) .
Be sure , that it's protection is good .
 
OK
so 900w 0-250v 0-15a
adjustable (if you wish with protection)

would you give me the schematics?
thanks for help
if you want mail me at

crackhead666@mail.bg
thank you
:smile::smile::smile:
you helped me alot

---------- Post added at 17:09 ---------- Previous post was at 17:04 ----------

sorry dude,but if it's possibe can you make it with adjustabe frequency

---------- Post added at 17:10 ---------- Previous post was at 17:09 ----------

thank you
you must be
godsmith
 
Last edited:

I thought we was here to help not do and give you the work, If your not good with micro controllers why not learn them, start off easy and work your way up, There is a good old saying learn to walk before you run
sounds like to me your going to be out of your depth with this one taking on a big project
 

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