Recent content by Michel Walsh

While that seems evident, a problem is that a DC power source is often from AA or AAA cells which can be installed in the reversed position. A connector is NOT involved to start with. Sure, the problem is not there if your power source is from an USB cable (or another similar unidirectional...

You can try to use a PMOS, as connected here: PMOS to protect against wrong polarity. Its advantage over a diode is that, when the polarity is "right", a smaller voltage reduction AND a much smaller POWER dissipated than for a diode forward biased. You can run the Simulation, without modifying...

Not an answer but a note of possible consideration (not having much detail): isn't it preferable to use a constant current source, such as 20mA for example, instead of a constant voltage source to which you add a variable limiting resistor itself dependent on the voltage at the LED?

Could it be an inductor of 220uH at +/- 15% tol. ? With an ohmmeter, if so, it should give something close to 0 ohm (in parallel with the board, that still makes 0 ohm).

From the web: 14500 battery specifications: Type/Size: 14500 battery Protected Battery Cell Capacity Maximum: 1115 mAh Battery Cell Capacity Minimum: 1040 mAh Battery cell Capacity Rated: 1100 mAh Energy: 4070 mWh [4.07 Wh] mWh=Milliwatt-Hour Chemistry: Li-ion [ Lithium-ion ] Nominal Voltage...