Transistor Electronic Circuits, page 5

Transistor Circuits, Page 5
Transistors: #'s A B-C D-G H-I J - O P - T - Z
Last Updated on: Wednesday, June 02, 2021 05:07 AM

Circuits Designed by Dave Johnson, P.E. :

High Impedance JFET Buffers
I have used these circuits many times. They are great when you need a low gain AC signal amplifier with a very high input impedance. It is good to beyond 50MHz.

Links to electronic circuits, electronic schematics and designs for engineers, hobbyists, students & inventors:

H-BRIDGE Theory & Practice - A number of web sites talk about H-bridges, they are a topic of great discussion in robotics clubs and they are the bane of many robotics hobbyists. I periodically chime in on discussions about them, and while not an expert by a long shot I've built a few over the years. Further, they were one of my personal stumbling blocks when I was first getting into robotics....[Chuck McManis]

High Current MOSFET Flip Flop with Debounced Pushbutton - This circuit was adapted from the "Toggle Switch Debounced Pushbutton" by John Lundgren. It is particularly useful in controlling a load from several locations where the load may be switched on from one location and switched off from another. Any number of momentary (N/O) switches or push buttons may be connected in parallel. The circuit....(electronic schematic / circuit added 11/05)

High Impedance JFET Buffers - I have used these circuits many times. They are great when you need a low gain AC signal amplifier with a very high input impedance. It is good to beyond 50MHz. …. [Designed by David A. Johnson]

High Power FM Microphone FM Bug - My FM Wireless Microphone has been a very popular project with beginners and experienced constructors alike. It has been used inside guitars and as the basis of a remote control system. …. [from Harry Lythall's website]

High-side driver feeds IGBTs and MOSFETs - 11/23/00 EDN-Design Ideas The low- to moderate-power system in Figure 1 provides the interface between a pulse-width modulator and a high-side IGBT (insulated-gatebipolar-transistor) or MOSFET switch. You can use it to interface TTL or CMOS circuitry to an H-bridge.... [Design idea by Carlisle Dolland, Honeywell Engines and Systems, Torrance, CA]

IC maintains uniform bias for GaAs MESFETs - 22-Aug-02 Issue of EDN The gate-turn-on threshold voltage for GaAs MESFETs (gallium-arsenide metal-semiconductor field-effect transistors] varies considerably from part to part, even within a given lot. That behavior makes biasing difficult, especially if you want to design the device into a high-volume product. To overcome this drawback, you can introduce a current sensor that monitors the bias current and provides.... [Design Idea by Ken Yang, Maxim Integrated Products, Sunnyvale, CA]

Improve FET-based gain control - 6-Dec-01 Issue of EDN One problemwith standard FET gain-control circuits is increased noise when you use the FET as a part of a resistive attenuator in series with an op amp. This configuration attenuates the signal before amplification; hence, it requires much higher gain bandwidth and better noise performance from the op amp.... [Design Idea by Ron Mancini, Texas Instruments, rmancini@ti.com]

Improved VBE Doubler - Circuit is a compensated Vbe doubler which operates over a wide current range.… [Jim Haggerman, Hagerman Technology LLC]

Inrush limiter also provides short-circuit protection - 9-Jun-05 Issue of EDN MOSFET keeps inrush currents due to capacitive loads under control.... [Design Idea by Ryan Brownlee, Process Automation Division, Pepperl & Fuchs Inc, Twinsburg, OH; Edited by Brad Thompson and Fran Granville]

Isolated MOSFET driver has wide duty-cycle range - 29-Apr-04 Issue of EDN The main application for the circuit in Figure 1 is for driving power MOSFETs with signals ranging in frequency from 1 Hz to 300 kHz and with duty cycles from 0 to 100%. You achieve this goal by using a coreless pc-board transformer. The switching frequency in most power-electronics circuits ranges from a few hertz to a few hundred kilohertz.... [Design Idea by Jesus Doval-Gandoy and Moises Pereira Martinez, ETSI Industriales, Vigo, Spain]

Isolation MOSFET-driver IC gets improved power efficiency at lighter loads - 8-Jan-09 Issue of EDN An isolation driver with feedback boosts 5V to approximately 13V, reducing power consumption.... [Design Idea by Marián Štofka, Slovak University of Technology, Bratislava, Slovakia]

Transistors: #'s A B-C D-G H-I J - O P - T - Z