Details of user Freddy
| Name: | Freddy |
| Joined on: | oct 24, 2007 |
| Status | Member |
| E-mail: | not public |
| Website: | meettechniek.info |
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| Address: | |
| ZIP/PC City: | |
| Country: | |
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| Notes: | I'm the owner of meettechniek.info. I founded this site because I noteced that many people didn't know how to perform measurements correctly. By writing articles about this subject I hope to spread knowledge and create awareness about this subject. |
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Comments by Freddy
| Date | Article | Comment |
| nov 05, 2022 13:12:00 |
Accuracy, precision & resolution | Thanks for spotting the typo. It is corrected. |
| sep 13, 2022 21:10:25 |
Golfvorm synthese generator | I got the harmonic amplitudes for the various waveshapes from a book: "PolyTechnisch zakboekje" PBNA 47e print page A2/76 ... A2/79. |
| jun 15, 2022 17:16:38 |
Arduino wattmeter | Hoi Jac, de analoge kanalen worden geselecteerd in: /*** Interrupt routine ADC ready ***/ ISR(ADC_vect) { ... Een aantal regels vanaf de start van de routine ... |
| apr 15, 2022 11:45:03 |
Measuring capacitance and ESR | Methode 1 & 2 obtain the capacitance and ESR independent of each other. Other type of measurements or with dedicated capacitance measurement devices you can ... |
| sep 03, 2021 14:19:49 |
Average & effective values | Sorry, I completely overlooked the additional text in the sub chapter. The mistake is corrected. Thanks! |
| sep 01, 2021 23:58:57 |
Average & effective values | 0 (zero) is the only correct value. You can check this for yourself: Measure the AC mains voltage with a multimeter placed in the DC-range . The DC-range will ... |
| jul 11, 2021 19:26:36 |
Magnetic circuits | Not only the amount of energy that can be stored changes by applying an air gap: Also the magnetic resistance of the magnetic circuit increases, and with that t ... |
| jul 11, 2021 14:41:38 |
Magnetic circuits | @Guy, you are right if the field strength H where constant in every section of the magnetic circuit, but it is not. On the other hand, the flux density B is con ... |
| jul 11, 2021 13:15:52 |
Magnetic circuits | The energy stored per volume in a magnetic field is calculated as: w = 0.5 * B^2 / μ How lower the permeability μ, how higher the stored energy per volume. Th ... |
| jul 10, 2021 20:52:55 |
Magnetic circuits | Are you trying to tell me that class-A amplifiers with output transformers are the main usage for transformers and inductors? Are these devices not a little bit ... |
| jul 10, 2021 11:48:35 |
Magnetic circuits | Air gaps are usually applied in inductors. The main reason is that you can store more energy (per volume) in air than in ferriete or iron. But making a the enti ... |
| jul 10, 2021 11:06:44 |
Oscilloscope probes | Maxwell says: don't look at me, look at Michael (Faraday). An object (core) that is magnetisize by an external magnetic field (a current through a wire) is ... |
| feb 11, 2021 20:36:25 |
Meetnauwkeurigheid | Je moet comments niet vergelijken met de inhoud van de artikelen. Ze zijn alleen bedoeld om mijn gedachtegang te verklaren of iets inhoudelijks te verduidelijke ... |
| feb 11, 2021 11:24:33 |
Meetnauwkeurigheid | Met figuur 1 wil ik laten zien dat het histogram is ontstaan uit het binnen van verschillende meetpunten. Om onderscheid tussen de individuele meetpunten te kun ... |
| jan 21, 2021 12:55:20 |
Additive synthese waveform generator | I don't know of an online instrument. But I think a midi keyboard with a Hammond organ simulation will do the trick. |
| nov 30, 2020 16:03:07 |
Fast Lux meter | Yes, the BPW34 is more sensitive, but its spectrum lays more in the near infrared region and does not represents the human eye. |
| sep 24, 2020 09:04:09 |
Arduino wattmeter | You don't have to modify the circuit. The wattmeter can measure negative voltages. Connect the current measure side so it measures also negative. The resul ... |
| aug 30, 2020 10:08:02 |
Additive synthese waveform generator | It is all in one JS file. Only the HTML elements are marked-up in this HTML file. And you can find the style descriptions in golfvormsynthese.css |
| aug 29, 2020 20:13:16 |
Additive synthese waveform generator | It is not open source, but you may use it for educational purposes. You can find the link to the javascript source (golfvormsynthese.js) in the HTML source code ... |
| mar 06, 2020 20:42:01 |
Arduino wattmeter | @Matt, You can monitor the (dis)charging at the battery as you wishes within the accuracy limits described in the article. To reduce the power consumption yo m ... |
| mar 06, 2020 20:26:16 |
Arduino wattmeter | @Raju, I'm sorry. To convert the code to another system is something to figure it out yourself. I don't have the time for it. Sorry. |
| mar 06, 2020 20:21:34 |
Arduino wattmeter | @Milli, No, 1024 is correct, that is the number which the reference must be divided by to get the step size. Suppose you have a reference voltage of 4 volt and ... |
| feb 04, 2020 11:27:37 |
Fast Lux meter | You can make the luxmeter less sensitive by lowering the value of R1. As An example: halving the resistance value dubbles the maximum range. And if you only int ... |
| feb 03, 2020 16:52:37 |
Fast Lux meter | The power supply voltage must be at least 12 V and may never exeed the OP37 absolute maximum rating of 22 V. The output voltage lays between 0 volt @ 0 lux, and ... |
| jan 28, 2020 10:07:03 |
Shuntweerstanden | Als ik mij niet vergis is die maximale aardweerstand van 166 Ω de weerstand van de hele keten, incl. de weerstand van de aardpin naar de grond. Je kunt du ... |