DIY Curve Tracer for PC

[NicMac]

Thanks Fred!
Is paint preinstalled on PC's with Windows?
Nic

[pchw]

Hi Nic,

Yes, paint comes with all versions of Windows (that I can remember). You can fire it up by typing "paint" in the run box or "Programs -> Accessories -> Paint".

One caution, typical Mac notebook keyboards don't have the <PRT SCR> keyword, at least not from my MacBook. If you are using Bootcamp to mutli-boot your Mac into windows, you will need to use an external KB, any 101 keys USB KB will do.

OT: spent a few days in Italy a couple weeks ago, lovely country.

Cheers,

[locky_z]

Originally Posted by NicMac

attached as PDF. No zip tool on the Mac.

BTW: what is the easiest way to get the PC clipboard content into to posts on this forum?

I have observed these data 2SJ, Ve of the voltage is stable,
I think that the Vce=15V is too large.
When the current is greater than 3.5A,the voltage drop of RC may more than 3.5×4.55=16V,
System may hard to keep Vce=15V, and the curve is confusion.

You can set Vce=12V and try again.

[buzzforb]

Locky,
I have tried many different things with the P channel parts. Dropping the Vce has no effect on the outcome of my test. The only thing that allows it to test to 2500ma is to set the Vb steps high at .500mV. It is if the rapid step ups are robbing the bjt of current somehow. I have yet to be able to get the diode test to work either. I have tested the Diode using standard non linear IV curve without any trouble. Replacement parts should be here beginning of week.

[NicMac]

Ok. I exchanged both the LM568 op-amps with new branded LT1013 op-amps (LT1013CP from TI - beware that the LT1013 come in different packages!).
The curves now look better, but the tracer still "panic" at currents above 3.2A.
What to try next dear locky_z?

P.S. @Fred: thanks for the tip on how to attach images in Windows!

[buzzforb]

Originally Posted by NicMac

Ok. I exchanged both the LM568 op-amps with new branded LT1013 op-amps (LT1013CP from TI - beware that the LT1013 come in different packages!).
The curves now look better, but the tracer still "panic" at currents above 3.2A.
What to try next dear locky_z?

P.S. @Fred: thanks for the tip on how to attach images in Windows!

NicMac,
Did reducing Vce affect your mesurements any?

[NicMac]

The change of op-amps also seem to improve on the "interval narrowing effect", when measuring N-channel DUT's, but still not good enough.

I think locky_z would have a lot to gain (earn) by collaborating with us here at diyAudio so I'm sure he will come up with the fixes needed!

Cheers,
Nic

P.S. N-channel DUT in brown.

[NicMac]

Originally Posted by buzzforb

NicMac,
Did reducing Vce affect your mesurements any?

No. Here @ 12V

[NicMac]

Better decoupling caps for the op-amp(s)?

[buzzforb]

Thanks NicMac. just for kicks, try upping your Vb steps to every .5V and see what happens.