Experimenting with an HF oscillator, I needed to control the varactor diode voltage in precise increments over a 2 V-10 V range. A buffered potentiometer was the obvious choice, and connecting two pots in series to give coarse/fine control...
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Control accurate incremental voltage steps with a rotary encoder
White-LED driver operates down to 1.2V supply voltage
Many LED drivers, using both charge pumps and inductors, are available to boost the 1.2 to 2.4 V available from single- and dual-cell NiMH (nickel-metal-hydride) batteries to the 3.6 V that white LEDs require...
Create a Versatile Voltage-Controlled Voltage Regulator Based on the LP2951
The LP2951 voltage regulator is commonly used in applications requiring a preset output voltage, which can easily be configured using two resistors. The device provides low dropout regulation over a wide range of output voltages ranging from 1.235 V to around 30 V...
John Roach: Remembering the personal computer era pioneer
Personal computer era pioneer John Roach passed away in Fort Worth, Texas, at 83. Though widely acknowledged as a marketing visionary, he is known to have played a pioneering role in commercializing the complete, pre-assembled computers during the 1970s...
Synthesize variable resistors with hyperbolic taper
In adjustable, frequency-selective RC networks, the reciprocal of an RC product, ωC = 1/RC, determines the corner frequencies of the network...
PWM Generators with Independent Adjustments
The circuits of PWM pulse generators with independent frequency and duty cycle adjustments are described. The first one uses the TLC555 IC and an external master pulse generator on the CD40106 IC...
Vishay Intertechnology Introduces New R25 Values for Automotive Grade, Glass Protected NTC Thermistors in 0603 and 0805 Case Sizes
Vishay Intertechnology announced that it has extended its NTCS0603E3.....T and NTCS0805E3.....T series of Automotive Grade, glass protected NTC thermistors in the 0603 and 0805 case sizes with new electrical resistance values at +25 °C (R25) ...
Current-Feedback Op Amps Save Power In Photodiode Apps
Current-feedback amplifiers offer high bandwidth with minimal power-supply current draw. However, they're rarely used as transimpedance amplifiers in photodiode applications due to the high current noise of their inverting inputs...
Isolated AC linear power control
Power control using the linear region of an active device, such as a MOSFET, is not an efficient option. However if the range of power control is restricted to the lower or upper end of the range, using the linear region is not a bad choice...
Sampling peak detector has shutdown feature
You face a serious problem in using a slow ADC with a fast peak detector. The circuit allows a slow ADC to measure a fast, sampled signal peak...
