Self-heated Darlingtion transistor pair linearly senses airflow using just two wires for both power in and signal out. Suppose we take a common TO-92 transistor and heat it to a constant temperature differential above ambient. The power input ...
Front-panel push button controls can conveniently adjust a PCB-mounted internal potentiometer’s resistance. Digital potentiometers in conjunction with MCUs find common use in analog circuits. The processor can adjust the gain of an amplifier, ...
Minimal circuit converts input frequency to a precision current source that also accommodates grounded inputs. I recently had the opportunity to share a design ( Ref. 1 ) for frequency to current loop conversion using the versatile (if somewhat ...
One of my electronics interests is building radios, particularly those featured in older UK electronics magazines such as Practical Wireless, Everyday Electronics, Radio Constructor, and The Maplin Magazine. Most of those radios are designed to run ...
I 2 C is a popular serial protocol for power controllers, ADCs and DACs, EEPROMs, and other devices. In certain data-acquisition and power-control situations, you must isolate the master from one or more slave devices for noise, grounding, or ...
There are times when you would like to control a DC motor using a simple +5 V logic swing signal. The circuit below performs this feat and also includes an automatic motor braking circuit. When the input logic signal swings from 0 V to +5 V, the ...
The circuit below can switch up to 4 Amps of current with a peak voltage up to 20 V. It is fully isolated using two inexpensive red LEDs. One LED forms a red light source, which illuminates a second red LED. The circuit takes advantage of the 1.5 V ...
In many applications, you would like to hold the speed of a motor constant, even as variations in the power supply voltage or mechanical load try to change its speed. In other applications, the average current to the motor needs to be limited, so ...
Single-cell lithium-ion (Li-ion) chargers are widely used, yet many practical designs rely on highly integrated ICs that conceal their internal operation. The type of Li-ion charger outlined in this design is, somewhat surprisingly, not readily ...
This easy-to-build PWM source is a handy testing tool for hobbyists, technicians, engineers and other RC-based device developers. I work at a university where I’m charged with designing and developing all manner of circuits and systems for ...