07:00 - the curve is 45 degrees, as our resistor in circuit is 3.3 kOhm and it just so happens the LoZ function in a Fluke 289 is about 3 kOhm. Curve will be between 0 and 90 degrees from horisontal, with the ratio of the 3.3 kOhm and the DUT resistor. The 2.2 kOhm at 08:16 gives us 2.2 kOhm / 3.3 kOhm = 0.67, counting the pixels we go up 1 division and left 0.6-0.7 divisions 🙂 Disclaimer: as long as scales are identical for A&B, else we need to multiply that in.
Very nice video. I'm definitely going to try this. I apologize ahead of time for this question, I'm new to electronics. For in circuit testing, wouldn't you want to use the higher value resistor? I figure it would lower the voltage so as to not turn on other components. Or maybe it doesn't matter ? Thanks, definitely subscribing.
Thanks for subscribing! There are some in circuit component combinations you can't test because of interaction of surrounding components. If you build the tester use whichever switch setting gives the better result. The lower resistance setting for in circuit testing should allow better drive of semiconductor junctions when paralleled by a resistance.
Cool basic videos. I really enjoy your tech talks. If anybody wants to built a slightly more complicated version of this, check out Mr Carlson's Lab channel where he has a circuit for a "curve tracer", which is essentially what Erik has built here. You have a little more control than shown here, especially if you don't have a variac. I think it's behind his patreon paywall but well worth a couple of bucks. For those new to this, it think easier to have the Y scale going the other way. I think it may just be a function of your X/Y setup? (Y seems to be more positive going down on your scope, which always seems backwards to me).
07:00 - the curve is 45 degrees, as our resistor in circuit is 3.3 kOhm and it just so happens the LoZ function in a Fluke 289 is about 3 kOhm.
Curve will be between 0 and 90 degrees from horisontal, with the ratio of the 3.3 kOhm and the DUT resistor.
The 2.2 kOhm at 08:16 gives us 2.2 kOhm / 3.3 kOhm = 0.67, counting the pixels we go up 1 division and left 0.6-0.7 divisions 🙂
Disclaimer: as long as scales are identical for A&B, else we need to multiply that in.
Very nice video. I'm definitely going to try this. I apologize ahead of time for this question, I'm new to electronics. For in circuit testing, wouldn't you want to use the higher value resistor? I figure it would lower the voltage so as to not turn on other components. Or maybe it doesn't matter ? Thanks, definitely subscribing.
Thanks for subscribing! There are some in circuit component combinations you can't test because of interaction of surrounding components. If you build the tester use whichever switch setting gives the better result. The lower resistance setting for in circuit testing should allow better drive of semiconductor junctions when paralleled by a resistance.
@EriksElectronicsWorkbench thanks for the information, definitely will do! 😀
👍👍👍
Cool basic videos. I really enjoy your tech talks. If anybody wants to built a slightly more complicated version of this, check out Mr Carlson's Lab channel where he has a circuit for a "curve tracer", which is essentially what Erik has built here. You have a little more control than shown here, especially if you don't have a variac. I think it's behind his patreon paywall but well worth a couple of bucks.
For those new to this, it think easier to have the Y scale going the other way. I think it may just be a function of your X/Y setup? (Y seems to be more positive going down on your scope, which always seems backwards to me).
@@larrybud Great advice 👍