Sometimes you need to know which wire/node is positive polarity and which wire/node is negative polarity.The LED as a polarity indicator circuit is show in above diagram. In the diagram as you can see ...

In production, this may be replaced with a zero Ohm resistor. The open circuit protection circuit shown utilizes R9, causing it to serve an additional function, in conjunction with Zener diode D2. In ...

This is a very simple arduino project where a led is turned on by setting the pin 13 as output, then write it with a high value, in our case that means that pin 13 will deliver 5 volts. Advertisement ...

In 10k quantities, the AL5809 Constant Current Linear LED Driver from Diodes Incorporated is priced at: $0.10 USD each for the SOD-123 packaged devices, $0.11 USD each for the 15-50mA parts in the ...