One of the questions that hobbyists ask over and over is how to select the value of a current limiting resistor for an LED. Usually the seat of the pants response is ...

A solar day lamp is a simple, inexpensive device for bringing “daylight” to dark interior spaces whenever the sun is shining. This article provides complete instructions for designing lamps using both ...

This paper dial makes selecting current limiting resistors a snap. [Giorgos Lazaridis] came up with the tool, which he describes in detail in the Worklog tab of his writeup. If you want one of your ...

If you got your start in electronics sometime after 1980 your first project might well have been to light up an LED. Microcontroller projects often light up an LED, too, and a blinking LED is ...

This file type includes high resolution graphics and schematics. LED-based lighting is replacing incandescent and gas-discharge lamps in many situations. As practical lighting sources, and considering ...

This resistor with bands of red, violet, yellow, and gold has a value of 270,000 ohms (270kΩ) with a tolerance of ±5%. \( \begin{eqnarray*}\text{R}_\text{t} &=& \frac{3.9 \times 6.8}{3.9 + 6.8} \\ &=& ...

There are many cases where a power supply needs an internal current-limiter function, usually built using a current sensor, a control circuit, and a pass transistor. The current sensor itself can be a ...

Linear constantcurrent drivers, for instance, offer low EMI, low cost, and use only a few components. Many designers favor them for low-current applications where power loss is a minor concern. If ...

Higher-than-normal operating voltages give steppers better torque at high speeds — but watch that current! • The inductance in a stepper-motor phase winding limits how fast current rises when power is ...