The article describes an RGB incident light sensor that uses colored LEDs as narrow-spectrum photosensitive elements. In the process of prototyping the RGB sensor, LEDs from the available batches were tested. However, the best results are obtained ...
You can use simple circuits to implement small, regulated plug-in power supplies. In Figure 1, a basic and versatile 5 V supply uses a zener diode and an emitter-follower transistor. You must calculate and design the transformer such that Q 1 is ...
The low-cost percentage-relative-humidity radio transmitter in Figure 1 operates in a cold-storage warehouse for vegetable storage at temperatures of 1 to 5 C. It is generally difficult to collect such data from a low-temperature area with high ...
For symmetrical applications, the circuit of Figure 4 works well. It is made up of the positive limiter already seen and a complementary negative limiter connected in parallel. A single positive reference voltage is used to control both voltage ...
I need a circuit to limit the voltage across some dissipation limited devices. It must: limit the voltage to a maximum of 1.5 V, have symmetrical limiting, be capable of accepting a current of 2 A, and leak less than 100 µA at 1 V. Two Zener ...
Three-phase VCOs (voltage-controlled oscillators) see service in many applications, including power inverters and in electronic-music synthesis as control and modulation sources. A previous Design Idea describes a basis for a simple, three-phase ...
CMOS devices have large input impedance with input currents on the order of 0.01 nA. Adding feedback circuitry can result in a latch-like device that can be used to store bits, and also operate in a more analog mode as shown in this Design Idea, ...
This Design Idea involves a low-power motion-detector circuit that operates from battery power for extended times. Part of the design includes a solenoid-operated trip mechanism that triggers whenever it detects motion. The drive circuit for the ...
The autoreferencing circuit in Figure 1 nulls out the error of a sensor, such as a pressure transducer, at its reference level for example, at ambient pressure. The circuit is an analog-digital-feedback control system that uses a digitally ...
Piezoelectric transducers find use in NDE (nondestructive-evaluation) applications. The PVDF (polyvinylidene-fluoride) transducer has many advantages, including a wide bandwidth and high sensitivity. These transducers require high-voltage and ...