I built an amplifier kit; it worked, but I realized that I forgot to trim the leads on the last component I put in - a 3mm LED. I disconnected the power and touched my cutters to the LED and got a spark. After trimming the LED leads, I reconnected power and the amp still worked, but the LED doesn't light. Probably, I discharged a 1000 μF filter cap through the LED.
The kit claims that the maximum voltage is 14 VDC, and power runs through a reverse polarity protection diode, so call the voltage 13.3. The LED was blue, so the Vf is maybe 3.5, and the current limiting resistor is 10k. Thus, the current through the LED is about 1 mA.
I don't find any blue 3mm LED's at that low current. Does anyone know of a source? Thanks.
The kit claims that the maximum voltage is 14 VDC, and power runs through a reverse polarity protection diode, so call the voltage 13.3. The LED was blue, so the Vf is maybe 3.5, and the current limiting resistor is 10k. Thus, the current through the LED is about 1 mA.
I don't find any blue 3mm LED's at that low current. Does anyone know of a source? Thanks.