This page has two unusual two-transistor oscillators. I set the component values for a low frequency application. Both circuits draw only about 1 microamp of current. Materials on the topic Datasheet Fairchild 2N3904 Datasheet Fairchild 2N3906 ...
Tracking down rodentia (or otherwise)-caused cable cuts, and differentiating them from normal open circuits, is critical. Evolving the circuit design for expanded functionality makes it even more valuable. It’s just part of the job. Every ...
My recent DI contribution (Another silly simple precision 0/20 mA to 4/20 mA converter, Ref. 1 ) used the LM337 regulator in a novel circuit arrangement to translate an input 0-20 mA current source into a 4-20 mA two-wire transmitter current loop ...
Recently, frequent Design Idea (DI) author Christopher Paul showcased an innovative and high performance true-two-wire current source using a depletion mode MOSFET as the pass device in “A precision, voltage-compliant current source” ( ...
Lively discussions have sprung up here in editor Aalyia Shaukat’s Design Ideas regarding the limitations and quirks of, and design tricks for, the current control topologies shown in Figure 1. Figure 1. How to control amps of I OUT with mA of ...
Almost every wall power supply has no indicator showing whether current is consumed by the load or not. It seems that this was a shortcoming that was not only noticed by me: I once saw the solution given in Figure 1. Figure 1. Wall power supply ...
LM317 fans will recognize Figure 1 as the traditional LM317 constant current source topology. It closely regulates I OUT = V ADJ /R S by forcing the OUTPUT pin to be V ADJ = 1.25 V positive relative to the ADJ pin. Thus, I OUT = V ADJ /R S to a ...
Receiving infrared (IR) signals while conserving system power is difficult, and typically requires the inclusion of complex power-management routines in the firmware. You can avoid that problem by disconnecting power to the microcontroller when IR ...
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 ...
This design idea revisits another: “PWM power DAC incorporates an LM317” ( Ref. 1 ). Like the earlier circuit, this one implements a power DAC by integrating an LM317 positive regulator into a mostly passive PWM topology. It exploits ...