How can I display the discharge of a battery from 13V to 12V so that the change is visible from the top of the display to the bottom. If I change the display to 0.2V/div it should fit, but I can’t change the Ypos enough to see it. All I can seem to do is display a flat line at the top of the screen. Auto gives 4V/div so the change will be less than one div. Not helpful.
That will not be possible, due to the screen resolution.
You will need to use a V/div setting that provides a good compromise.
Please tell me what settings will show anything other than a flat line. I understand the resolution, I just want to see the bit of the display from 12 to 13 Volts.
Sorry, but that is impossible for us to tell, as this depends on the time required to drop from 13V to 12V.
You are missing my point. The only settings that show the line at all are 4V/div - 20V/div. All flat lines. That’s no use for looking at a one volt drop. Is it possible to display the 12-13V range at any setting less than 4V/div. The time setting doesn’t matter when you can’t see the line at all!
I just want to set the scale and then scroll the display.
Your site has a video showing battery discharge over a long period. Looks good, but I can only assume you showed 12 - 0 volt discharge, which kills batteries, or you were using a different firmware which works. I can’t get a similar display to show 13-12V discharge. My firmware version is 1112.
As we explained before, if you insist on displaying 13V and still require high resolution to see a 1V drop, you will need a different approach.
You could e.g. put a 10 or 12V zener diode in series with the probe. This will provide necessary drop, so that you can set the unit to a lower V/div, which wil result in higher resolution.
All you said was [quote]That will not be possible, due to the screen resolution.
You will need to use a V/div setting that provides a good compromise.[/quote] and [quote]Sorry, but that is impossible for us to tell, as this depends on the time required to drop from 13V to 12V.[/quote]
I do not want to display 13V, I want to display the 1V between 12 and 13. Even a ‘toy’ oscilloscope should be able to do that.
Anyway I’ve returned the ‘toy’ and got a refund. Good luck!
[quote=“bobinski”]I want to display the 1V between 12 and 13. Even a ‘toy’ oscilloscope should be able to do that.[/quote]Actually that is not so, and your saying it says more about your lack of knowledge than any shortcoming of the HPS140. So instead of getting snotty you need to better understand what you are asking, as it is beyond the reach of many oscilloscopes.
To do what you ask–display that 1V differential floating on a 12V offset across even the topmost 5 divisions–would require vertical gain of 200mV/division and that that the Y-offset be -12.2V (-61 divisions at 200mV/div) just to move the +13V level to the top of the display.
Though there are exceptions, at that gain most 'scopes typically offer a +/- 10V offset.
To make the observation you wish you will need to remove the DC offset. A way to do that is by using a Zener diode is series as suggested by Velleman. Shown below I have used two Zeners, a 5.6V and a 6.2V in series with the probe, this will reduced the DC offset to 0.8V or so moving the 13V to 12V differential you wish to observe to a range of 1.8V to 0.8V; with reasonable accuracy for such a simple solution.
Thanks Cliffyk for taking the time to elaborate on my proposal to the customer.
You are quite welcome, one cannot fault a fault an apple for not being a peach…
Cliffy,
Once again, Well said
cliffyk,
Thank you for you explanation. You are quite right, my knowledge is indeed limited, and if I had your reply first I would not have got 'snotty'. You seemed to understand what I was asking when Velleman didn't. I just saw red when I was told "As we explained before, if you insist on displaying..." as if my insistence was unreasonable.
I'd already been told twice that it was impossible, or needed a compromise setting when there isn't one at all, no explanation anywhere! The first mention of diodes was after this - too late, I'd already thrown my toys out of the pram!
At least anyone else in my situation might choose more carefully now.
I'm not going to buy one again without being able to see a proper user guide first.
bobinski.
I have to agree that the user’s guide and specifications leave quite a bit to be desired.
For what you wish to observe you may want to look at the [color=#0000BF]Velleman PCS10/K8047 data logger[/color] it would be better suited to the battery discharge monitoring, costs less, and lets you save the data to a PC.
We understand that the low-cost HPS140 will be purchased by a lot of people who have less experience with oscilloscopes.
Therefore, we are planning the release of a small educational board (EDU06), which will generate a number of signals which are interesting to display on a scope, in order to understand its operation, familiarise the user with its features and functions and to learn the basics of measuring. All experiments will be based on the HPS140.
[quote=“VEL417”]We understand that the low-cost HPS140 will be purchased by a lot of people who have less experience with oscilloscopes.
Therefore, we are planning the release of a small educational board (EDU06), which will generate a number of signals which are interest to display on a scope, in order to understand its operation, familiarise the user with its features and functions an to learn the basics of measuring. All experiments will be based on the HPS140.[/quote]
That sounds neat–a great idea!