A simple current source It has long been known that the simple combination of a depletion-mode MOSFET (and before these were available, a JFET) and a resistor made a simple, serviceable current source such as that seen on the right side of Figure ...
A classic nonlinear analog function is the squaring circuit. It’s useful in power sensing, frequency multiplication, RMS computation, and many other odd jobs around the lab bench. Figure 1. The squaring amplifier that is fast, ...
“Facts are stubborn things” (John Adams, et al). I added two 50-ohm outputs to the schematic of my published voltage-to-frequency converter (VFC) circuit [ 1 ] (Figure 1). Then, I designed a PCB, purchased the (mostly) surface-mount ...
Recently, we’ve seen Design Ideas for programmable current sources with improved accuracy using the LM3x7 series of three-legged regulators. These designs also take advantage of those classic devices’ built-in anti-overheating features. ...
The project presented here is a professional quality phantom powered microphone pre-amplifier (Figure 1). The project is built using the INA163 chip from TI. The Chip is a very low-noise, low-distortion, monolithic instrumentation amplifier. R2 and ...
Brief intro to vactrols Vactrols, or both an LED and a light depending resistor (LDR) ( Ref. 1 ) in a light-tight housing, are found in analog music electronics circuits like audio compressors, voltage-controlled amplifiers (VCAs), ...
My Design Idea (DI), “Flip ON Flop OFF for 48-VDC systems“ ( Ref. 1 ), was published and referenced Stephen Woodward’s earlier “Flip ON Flop OFF” ( Ref. 2 ) circuit. Other DIs published on this subject matter were for ...
Some applications require a hot-swap controller, a circuit-breaker function, or both for dual-polarity, dc-input power-supply rails. In some hot-swap cases, the requirement is based only on inrush-current considerations. Control of the inrush ...
A simple, permanent-magnet dc motor is an essential element in a variety of products, such as toys, servo mechanisms, valve actuators, robots, and automotive electronics. In many of these applications, the motor must rotate in a given direction ...
This circuit uses a low power op Amp and a p-channel FET to form a diode function with a very low 0.05 volt voltage drop. With the selected FET, the circuit can handle up to 2 Amps of current. Higher currents are possible with a FET with a lower ...