Circuits & Schematics - 2

There’s been a lot of interesting conversation and DI teamwork lately devising circuits for ON/OFF power control using inexpensive momentary-contact switches (See Ref. 1 Ref. 4 ). Most of these designs have incorporated edge triggered ...

Dual precision comparators are needed in many designs, such as for industrial and instrumentation applications, to generate accurate pulse-width modulated (PWM) waveforms with very high ( 99%) and very low ( 1%) duty-cycle percentages. This design ...

A stable voltage from an input supply that is higher and lower than the output is often required. A common solution is to use a boost converter followed by an LDO as shown in Figure 1. The boost converter is configured to accept voltages ranging ...

This modular resistor load bank uses a unique topology to reduce the number of switches and resistors while providing the maximum number of steps. An array or bank of load resistors is often required for testing power products, characterization of ...

Introduction In general, muting and/or signal switching is done by relays, FETs or CMOS analogue switch ICs. All have limitations, but a little known technique that really doesn't look like it could ever work is to use bipolar transistors. The ...

Famous analog designer and author Jim Williams published an awesome design in 1986 for a 100-MHz voltage to frequency converter ( Ref. 1 ). He named this high-climber (picture it on the roof of the Empire State building swatting biplanes out of the ...

Frequent design idea (DI) contributor Nick Cornford recently published a synergistic pair of DIs “A pitch-linear VCO, part 1: Getting it going” ( Ref. 1 ) and “A pitch-linear VCO, part 2: taking it further” ( Ref. 2 ). The ...

In Part 1, we saw how to make an oscillator whose pitch, as opposed to frequency, can be made proportional to a control voltage. In this second part, we’ll look at some alternative ways of arranging things for other possible applications. To ...

If you've ever designed an RF oscillator, you've probably encountered squegging. Sometimes called motor boating, squegging causes oscillators to start and stop at frequencies much lower than the frequency of interest. Viewed on an ...

The recent Design Idea “Getting an audio signal with a THD 0.0002% made easy” [ 1 ] discloses a low THD sine generator which led me to dust off a design that I had published in AudioXpress magazine [ 2 ] (see Figure 1). Figure 1. A ...