Timeline for 0 - 70mA led driver
Current License: CC BY-SA 4.0
8 events
| when toggle format | what | by | license | comment | |
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| Dec 2, 2019 at 2:24 | comment | added | D.A.S. | 50 mV drop is std for Current sensors to 1) minimize voltage drop 2) reduce waste heat 3) reduce need for a large power resistor. | |
| Dec 1, 2019 at 3:13 | history | edited | D.A.S. | CC BY-SA 4.0 |
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| Nov 30, 2019 at 9:43 | comment | added | VinFar | I will have a look at photodiodes, this may be the better solution. That's a great idea with the laser! With a focused beam, it will be able to only detect the disk and not the white metal sheet behind it. Could you explain me, why a lower Rsense would be better? I thought that a high Voltage will increase the SNR for the Opamp. | |
| Nov 29, 2019 at 13:04 | comment | added | D.A.S. | yes it may be possible to use a laser mouse which has a low res optical imager if one probes around the chip pins for reflection signals. | |
| Nov 29, 2019 at 7:48 | comment | added | Russell McMahon♦ | I did this for a prototype some years ago. A very likely major issue for the OP is that they may not have access to the meter interior - ie Meters are usually security sealed - so he may not be able to either mark the disk or be able to optimally position the sensor. I had to work through the meter front glass using the existing black on white stripe. This was feasible with adequate playing and a largish area light shield patch over the outside to much diminish ambient light in the sensor area. | |
| Nov 28, 2019 at 23:02 | history | edited | D.A.S. | CC BY-SA 4.0 |
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| Nov 28, 2019 at 22:53 | history | edited | D.A.S. | CC BY-SA 4.0 |
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| Nov 28, 2019 at 22:47 | history | answered | D.A.S. | CC BY-SA 4.0 |