Hi,
I'm testing a OpAmp with a comparator to show that when my Vin gets a higher voltage than Vref it will let my Vcc+ pass through to my Vout. I'm using a LED LG2640, and the minimum voltage for it to lit is 1.7V at 20mA. But when i set my Vcc+ to 1.7V it won't lit the LED. I need to turn my Vcc+ to 3.5V, and at that moment it lights up, and i can measure a voltage at 2.0V running through the LED.
But why do i need it to be 3.5V for letting 2.0V through? I'm using a LM324 OpAmp with a comparator - It seems like (from the data sheet) it can run from as low as 3V. But why do i need to turn it up to 3.5V for it to let 2.0V pass through?
Hope you understand!
Let me know if there is something that need explanation.
I'm testing a OpAmp with a comparator to show that when my Vin gets a higher voltage than Vref it will let my Vcc+ pass through to my Vout. I'm using a LED LG2640, and the minimum voltage for it to lit is 1.7V at 20mA. But when i set my Vcc+ to 1.7V it won't lit the LED. I need to turn my Vcc+ to 3.5V, and at that moment it lights up, and i can measure a voltage at 2.0V running through the LED.
But why do i need it to be 3.5V for letting 2.0V through? I'm using a LM324 OpAmp with a comparator - It seems like (from the data sheet) it can run from as low as 3V. But why do i need to turn it up to 3.5V for it to let 2.0V pass through?
Hope you understand!
Let me know if there is something that need explanation.
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