What type of zener diode is this? The thin band is blue.
Best Answer
Other than the package looks like LL34, it's impossible to tell from the picture. The wide yellow band is almost certainly marking the cathode end. The line in the middle is not a marking band, but a artifact of construction.
You can try measuring the voltage across these diodes in normal operation. Keep in mind that for a Zener diode in Zener mode, the cathode is positive. If these are used as voltage references, that may work. If they are for clamping or other intermittent purpose, you may get lucky looking at the waveform over time. Otherwise, remove the didoes from the board and see what voltage they develop with about 1 mA reverse current.
Yes, it's the cathode. Don't take my word for it, it's easily tested with a multimeter; the voltage drop with this line negative should be 0.6V or so, the same as any other Si diode. To see the zener voltage, connect it reverse biassed (thin line positive)
Best Answer
Other than the package looks like LL34, it's impossible to tell from the picture. The wide yellow band is almost certainly marking the cathode end. The line in the middle is not a marking band, but a artifact of construction.
You can try measuring the voltage across these diodes in normal operation. Keep in mind that for a Zener diode in Zener mode, the cathode is positive. If these are used as voltage references, that may work. If they are for clamping or other intermittent purpose, you may get lucky looking at the waveform over time. Otherwise, remove the didoes from the board and see what voltage they develop with about 1 mA reverse current.