In Part 1 of this Design Idea [ 1 ], we saw how a standard electret microphone capsule can be persuaded to detect infrasonic signals down to a fraction of a Hertz by adding some fairly simple equalization. In this second and concluding part, we ...
Figure 1’s negative constant current source has been a textbook application for the LM337 regulator forever (or thereabouts). It precisely maintains a constant output current (I OUT ) by forcing the OUTPUT pin to be the negative V ADJ ...
This design idea (DI) takes an unusual path to a power-handling DAC by merging an upside-down LM337 regulator with a simple (just one generic chip) PWM circuit to make a 20-V, 1-A current source. It’s suitable for magnet driving, battery ...
Figure 1 shows how to position a mechanical device into four discrete positions but with only two free outputs and one free input from the control system. The position depends on a set of cams and four corresponding limit switches. The 24V-dc motor ...
As a genre, DACs are low power devices with power and current output capabilities limited to the milliwatt and milliampere range. There is, of course, no fundamental reason they can’t be teamed up with suitable power output stages, which is ...
The fuse described in this design idea does not drop the connection, it simply limits the output current. A behavior that is similar to a polyfuse, however the circuit shown in Figure 1 is more accurate, does not depend on ambient temperature ...
Systems using line receivers for differential input signals require an adequate self-test capability. Using an LM339 (a quad differential comparator), you can provide this capability by constructing the configuration shown in the Figure 1. ...
The popular I 2 C communication standard manages to perform flexible serial I/O with just a super simple two pin bus: SCL and SDA. It accomplishes this trick with bidirectional timing and data flow. Bidirectional flow is good at saving pins but due ...
The circuit in Figure 1 is a single-supply version of a programmable Schmitt trigger, or a comparator with hysteresis. A comparator, A1, and a digitally programmable potentiometer (DPP1) are used for the function. The lower (V LL ) and upper (V UL ...
Using a blue LED can pose problems when available power-supply voltages don't meet or exceed the LED's 3 V forward-voltage drop. This Design Idea shows how to drive a blue LED from a 3 V battery or another power supply. The circuit in ...