Comment summary #51
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Comment 501 ... 510
| date | article | author | comment |
| 10 feb 2014 02:58:14 | Fast Lux meter | steve | Thanks for the explanation so far. I will be constructing the hardware soonest; as time goes on, I will let you know the outcome of the work... |
| 10 feb 2014 02:27:26 | Fast Lux meter | Freddy | > Ques-1: Using a cheap voltmeter, I hope connecting the positive terminal to Vout and the negative terminal to Ground pin is correct? Yes, thats correct. > Quest-2: In the Lux-meter circuit diagram, pin 3 of OP37 is connected to Ground pin; True or False. Yes, this also true. > If true, what about the 0 line that is connected to pin 4 of OP37. The zero volt power supply is not the same as the ground. It is only the reference for the positive power supply. If your using the ground as power supply zero reference, than you can connect pin 7 to +5V and pin 4 to -5V. |
| 10 feb 2014 02:15:18 | Fast Lux meter | Freddy | Repeating the question doesn't help to clear things. Connecting to an ADC-converter is simple. Connect the ADC in- and supply ground to the Lux meter ground. The opamp output goes to the ADC in+. Use the 5V ADC supply also for the Lux-meter positive supply. And use an extra negative 5 volt supply for the negative opamp power connection. |
| 10 feb 2014 02:08:28 | Fast Lux meter | steve | Thanks for your reply. Sorry I am asking much; I have two questions: Ques-1: Using a cheap voltmeter, I hope connecting the positive terminal to Vout and the negative terminal to Ground pin is correct? Quest-2: In the Lux-meter circuit diagram, pin 3 of OP37 is connected to Ground pin; True or False. If true, R3, C3, C5 are connected together to pin 3 of OP37 and also to Ground pin. If true, what about the 0 line that is connected to pin 4 of OP37. Pls make it clear to me, Is pin 3 of OP37 connected to Ground pin? |
| 10 feb 2014 01:46:09 | Fast Lux meter | steve | Thanks for your reply. Sorry I am asking much; I have two questions: Ques-1: Using a cheap voltmeter, I hope connecting the positive terminal to Vout and the negative terminal to Ground pin is correct? Quest-2: In the Lux-meter circuit diagram, pin 3 of OP37 is connected to Ground pin; True or False. If true, R3, C3, C5 are connected together to pin 3 of OP37 and also to Ground pin. If true, what about the 0 line that is connected to pin 4 of OP37. Pls make it clear to me, Is pin 3 of OP37 connected to Ground pin? |
| 10 feb 2014 00:50:18 | Fast Lux meter | Freddy | If your only goal is to know the light intensity value, than the most simple solution is to buy a cheap multimeter and measure the output voltage. Multiply the read voltage by 2000 to get the Lux value. Or do you need an AD-converter to connect it to a computer? |
| 09 feb 2014 23:57:44 | Fast Lux meter | steve | Thanks for your reply. It is not yet clear to me how we can read the Lux value using a Seven Segment Display OR LCD Display. I thought of using Analogue-To-Digital Converter like ADC0804 and 7-Segment Display but the connection from the Vout of the opamp to an ADC0804 and 7-Segment is what I need...Pls I need more explanation on How to read the Lux value.. |
| 09 feb 2014 15:39:28 | Fast Lux meter | Freddy | It depends on the type of LCD voltmeter you have. The voltage representing the light intensity is the opamp output voltage relative to the ground. Not all volmeter modules have floating inputs, so it could be that you must use seperate power supplys for the LCD module and the Lux-meter. |
| 09 feb 2014 02:00:34 | Fast Lux meter | steve | Please, can you show the connection of the Vout to a display unit like LCD... |
| 01 feb 2014 16:27:39 | Magnetic hysteresis | Freddy | Varying the series resistance with a fixed generator voltage is als usable but will give different output signals because the impedance is not the same. But this has no effect on the final result. |