Milliohmmeter measures internal resistance of batteries, too
Check the condition of your car battery by measuring its internal resistance, without discharging it. Also track shorts and measure with high accuracy all kinds of low resistances: shunts, PCB tracks, contact resistances, relays, chokes and various windings, RTD sensors, etc.
This instrument is based on an AC low current very low frequency 4-wire resistance+ inductance measurement technique, which solves the issues of DC measurement errors. And it has the ability to measure the internal resistance (+ voltage) of DC current sources, with optional DC bias.
There are 4 measuring ranges from 1 up to 1000 ohms (best resolution of 10 microohms) with manual or automatic selection.
Powered by a standard 9V alcaline battery.
All details in the attachments.
There are 4 measuring ranges from 1 up to 1000 ohms (best resolution of 10 microohms) with manual or automatic selection.
Powered by a standard 9V alcaline battery.
All details in the attachments.
Discussie (13 opmerking(en))
RikV 2 jaar geleden
henrip4 2 jaar geleden
RikV 2 jaar geleden
I am desperately seeking for drop-in replacements. Hard thing.
RikV 2 jaar geleden
henrip4 2 jaar geleden
RikV 2 jaar geleden
I am consolidating the bill of material towards Mouser. Parts availability is still a problem.
Regarding the PCB I have a problem with the drill file LRM19A.exl. I loads faulty. The coordinates are scaled down by 10 but the hole diameters are correct. This is with Flatcam as well as Gerbview. What software are your files extracted from? Did the PCB manufacturer manage to read the file correctly?
You know of a drop-in replacement for the ISL28633? It will be months before it comes available.
henrip4 2 jaar geleden
Unfortunately, I have no alternative part for these ISL28633 zero drift PGAs. Actually, today's availability of any active component is really an issue.
RikV 2 jaar geleden
By the way, JLCPCB comes to 8.95€ for 5 pieces of the board and 24.99€ SH cost.
henrip4 2 jaar geleden
I didn't experiment JLCPCB, but 8.95€ seems to be a good price, I think it was more expensive with Eurocircuits, but for only 2 pieces.
RikV 2 jaar geleden
Do you have a detailed functional description available?
Stéphane, I do not pretend to be native English speaking, and by the way: Elektor (Elektuur) is not a French but a Dutch magazine.
Let's focus on the subject please.
henrip4 2 jaar geleden
I didn't write the detailed functional description yet. Such a documentation (in English, not my mother language) requires much time. However, you may ask me about any subject (like DL2-DL3).
RikV 2 jaar geleden
henrip4 2 jaar geleden
And very important for the protection of the instrument, this configuration is functional even when the power is off.
RikV 2 jaar geleden
But equipment should not be more expensive than really necessary. I understand tha many of the component choises have been made on a "I have this at hand so I don't have to buy it" basis.
However some of the componenet are excessively expensive since there are much cheaper alternatives available.
One example is the display. Over 16€ at Mouser (not counting the extra components) but an ordinary 1602 LCD only costs 4 or 6€! Add 2€ and you have I2C interface. I would prefer to spent that mony on an external RerVoltage for the DAC with significantly better tempco and drift specs (about €20 for 2ppm/K).
If ever you are planning to make a revision to the PCB please include these items as an option?
henrip4 2 jaar geleden
And about the DAC, thanks to the ratiometric configuration used, reference drift doesn't appear in the measurement result.
Stéphane PEREZ 2 jaar geleden
of the componenet are => component ?
that mony on => money?
etc... Look at yourself !
Vladimir I. Yershov 2 jaar geleden
https://aliexpress.ru/item/1005001926986935.html?
FR0130893ID 2 jaar geleden
En Français ce serais bien
Cordialement
henrip4 2 jaar geleden
Cordialement.
Renaat Wendrickx 2 jaar geleden
Stéphane PEREZ 2 jaar geleden
A noté que je n'ai pas de soucis de lecture, mais ça me laisse moins de doute lors de la lecture d'un article.
RikV 2 jaar geleden
Stéphane PEREZ 2 jaar geleden
Bonne journée monsieur Parfait!
Hevandyr 2 jaar geleden
Dj831 2 jaar geleden
henrip4 2 jaar geleden
I added I think all the missing files needed to build the project.
Dj831 2 jaar geleden
I think I will give a try to your very nice project next time I place an order to JLCPCB.
Out of curiosity, how did you make a such smart front panel? Did you use one of these chinese CNC?
Thanks and greetings from a place between Le Havre and Fécamp :)
henrip4 2 jaar geleden
En fait, je fabrique moi-même la plupart de mes pièces mécaniques. J'ai taillé ma face avant dans une plaque d'aluminium anodisé de 2mm (de récupération), détourage à la scie et finition à la lime, les trous sont faits à la perceuse sensitive. Le marquage est une étiquette transparente autocollante imprimée sur laser (pas très facile à positionner, et attention aux bulles d'air). Le boîtier est de la tôle d'acier de 1mm (de récupération aussi) pliée sur les grands côtés, avec les 2 extrémités haute et basse soudées à l'étain-plomb. Finition avec apprêt plus peinture pour carrosserie. Comme je dispose d'un tour, je fabrique également sur mesure mes boutons, entretoises, etc.
Je fais fabriquer tous mes circuits imprimés chez Eurocircuits. Je connais JLCPCB de nom, mais je ne l'ai pas expérimenté, c'est à priori moins cher.
J'ai 2 résistances étalon AOIP: 0.001 et 0.01 ohm. J'aurai préféré en avoir une de 1 ohm, mais c'est pratiquement introuvable aujourd'hui. J'ai donc acheté des résistances de référence de chez Vishay que j'ai placées dans ces fameux boîtiers Teko P1 (j'ai racheté l'année dernière une dizaine de ces boîtiers chez Conrad, j'avais utilisé le dernier de mon stock pour mon projet "failsafe continuity tester").
Merci de votre intérêt à ce projet très marginal et salutations depuis la pointe Sud de l'Yonne!
Kabron 2 jaar geleden
Где смысл
henrip4 2 jaar geleden
After your first question, you began a new sentence, but there is missing text. Could you complete so that I may answer ?
ElektorLabs 3 jaar geleden
henrip4 3 jaar geleden
I have a few other documents, but they are not English translated yet.
Content Director, Elektor 3 jaar geleden
henrip4 3 jaar geleden
This amount doesn't include the home made enclosure and miscellaneous mechanical parts. However, components were bought at unity (or close to) prices. As you can see, this is actually not a cheap project. And today, with the shortage of components, the cost will still be higher, unfortunately.