DIY Curve Tracer for PC

[NicMac]

Originally Posted by locky_z

On any tabular data,you can right click, and select copy to clipboard, and then goto to EXCEL, paste the data.

If I have many traces in a file how do I copy all of the to clipboard?
One by one?

[locky_z]

Originally Posted by NicMac

I will try. Any suggestions for starting values?

the PCB is

The protect circuit


In circuit the 'R*' is the ‘Green’ color resistor on PCB picture
The Resistor of connect to 2SA970 base(18K) is Above 15V zener,SomeBoard may be 56K.

You can first remove the R *, and then measure the power transistor , large current Vce-Ic curve, you can see the curve turning point was the maximum protection current, and then according to the schematic calculate R*.

Originally Posted by NicMac

If I have many traces in a file how do I copy all of the to clipboard?
One by one?

You need copy and paste one by one.
Or
You can use Excel to open the cuv file (File -> Open ->File type(All file))
The save file '.cuv' is txt type file and with ‘Tab-delimited’.

[alazira]

Originally Posted by locky_z

to NicMac:
measure FET ,you can insert G to B / S to E / D to C
and press 'Load Condition' button to load ‘N-JFET Vgs-Id(Fix Vce)’ measurement conditions,

The measurement conditions mean
1. It set Vb from -5V to 0V step 0.1V mean Vgs from -5V to 0V step 0.1V
2. Set constant Vce=10V mean Vds is fixed at 10V.
3. RB=6K mean Gate protect resistor choice 6K ohm
4. RC=75 mean drain current sample resistor is 75 ohm.
5. Imax=30mA mean measurement end at current reaches 30mA.

Hi locky_z,
I would like to find the Idss value. Is this where Vb=0 on the x-axis?

[locky_z]

Originally Posted by alazira

Hi locky_z,
I would like to find the Idss value. Is this where Vb=0 on the x-axis?

Yes

However, due to the problem of measurement accuracy, there will be a few mV of error. When Vb=0，in fact Vb may be 5mV or -3mV,

So I suggest, If you want to measure Idss,you can short Gate & Source,and then put them into E socket. drain insert into C socket, and load 'NPN Vce-Ic' or 'NMOS Vds-Id' condition to measure.

Short gate and source of the JFET as a constant current diode,This ensures that Vgs = 0,
Because B socket is NULL, So the condition of 'Vce-Ic' or 'Vds-Id' can be considered a two terminal device that connect C & E measurement conditions,

After get the curve, It parallet to X-axis, the corresponding Y-axis is Idsss.

[RNMarsh]

I know this is a construction site and I dont want to take away the fun and time you are spending building from scratch -- However, anyone can buy a complete with CRT readout curve tracer from China --- Brand: SMT MAX, Model CA4810A curve tracer. Looks like a compact version of the Tek 576 but is new and does some things the old Tek doesnt. I bought one via the Internet and have used it... If this Pc version ever makes it to commercial market status, I'd buy one built.

[Lazybutt]

Originally Posted by RNMarsh

I know this is a construction site and I dont want to take away the fun and time you are spending building from scratch -- However, anyone can buy a complete with CRT readout curve tracer from China --- Brand: SMT MAX, Model CA4810A curve tracer. Looks like a compact version of the Tek 576 but is new and does some things the old Tek doesnt. I bought one via the Internet and have used it... If this Pc version ever makes it to commercial market status, I'd buy one built.

As far as I can see what you're talking about is about 9 times the price, weighs 13 kg (not to mention the shipping cost), and draws analog curves on a CRT screen...
On the plus side, it goes HIGH in voltage

The DIY curve tracer for PC does this digitally, (allowing printing, exporting, comparing, etc...), needs 5 minutes to setup, and weighs 2 kg

I think we're comparing carrots and potatoes here.

[sdman]

How difficult would it be to convert the curve tracer to a scope/crt readout?

sam

[NicMac]

Originally Posted by sdman

How difficult would it be to convert the curve tracer to a scope/crt readout?

sam

connect a PC with a CRT monitor

[sdman]

No PC.

From the curve tracer to an analog Oscilloscope.

I have an Tek 2465 that I would like to interface to the CT.

sam

[NicMac]

No chance...
The CT output USB or serial data so you need a PC.