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Underpinning knowledge
Published in Allan W. M. Bonnick, Vehide Electronic Systems and Fault Diagnosis, 2014
In the Darlington transistor two transistors are coupled together (cascaded) so that the emitter current of the first transistor becomes the base current of the second one. In this way the current gain is the first transistor’s gain multiplied by the second transistor’s gain.
Automated spectrophotometric platform for the quantification of multiple nucleic acid samples
Published in Instrumentation Science & Technology, 2021
Hoon Kang, Sang-Ryoul Park, Ju Hwang Kim, In-Yong Park, Hee-Bong Yoo, Inchul Yang, Haewon Jung
As shown in Figure 2, all electrical components of the novel automated spectrophotometric platform are linked and controlled with an integrated control system. This integrated control system is operated based on Embedded Linux with the Arm cortex-a8 processor (Myc-c335x, Myir Tech, China). In the novel automated spectrophotometric platform, the four pumps (two air/vacuum pumps and two peristaltic pumps) and the six solenoid valves (three 2-port and 3-port valves each) are controlled by general-purpose input/output (GPIO) signals that switch the Darlington transistor arrays (Uln2003a, STMicroelectronics, Swiss). Moreover, the pulsed xenon flash lamp and miniature spectrometer are triggered directly through other GPIO signals. The triple axis stepping motor driver (Tmcm-3110, Trinamic Motion Control GmbH, Germany) and the spectrometer are operated using serial communications (RS-485 and USB, respectively) to transfer commands and gather information. Because the functions for operating the components are modularized, the measurements can be performed automatically by executing related functions sequentially.
Sensor-triggered sampling to determine instantaneous airborne vapor exposure concentrations
Published in Journal of Occupational and Environmental Hygiene, 2018
Philip A. Smith, Michael K. Simmons, Phillip Toone
An ATmega328 microcontroller (Atmel Corporation, San Jose, CA) running at 16 Mhz was used to read the analog signal provided by the PID sensor and open a solenoid valve when trigger conditions were met. To match the full range of the sensor, a reference of 2.5 V was provided to the 10-bit A/D converter within the microcontroller by an A1117 voltage regulator. For triggered sampling a TIP120 Power Darlington Transistor was used for microcontroller actuation of a solenoid valve. An HC-05 Bluetooth Serial Port Protocol module allowed communication between the microcontroller and an Android tablet. The Bluetooth Electronics app by Keuwlsoft (London, UK) was used to display the output of the sensor and change the parameters used to define the sample triggering condition with the tablet device. Figures 1A and 1B show the important system components and sensor placement in the sampling plenum of the test atmosphere generator.
Kronecker Product Based Modeling of Darlington Amplifier and State Estimation using Unscented Kalman Filter
Published in International Journal of Electronics Letters, 2022
Amit Kumar Gautam, Sudipta Majumdar
Darlington amplifier has been used in various applications including broadband high-data-rate communication systems. The three-stage Darlington feedback amplifier presents better stability than single-stage Darlington feedback amplifier. DA circuit has been used in various broadband circuits. In addition, it has high-speed applications. Besides these, it is also used in low-noise amplifier (Lee & Cressler, 2006), mixer (Tsai etal., 2005), power amplifier (PA)(Kuo etal., 2013), distributed amplifier and active baluns (Weng etal., 2009). The DA is also used as a benchmark for verification of compact models at millimeter-wave frequencies (Mukherjee et al., 2016). Shukla and Pandey (2014) used DA together with Sziklai to model two-stage small-signal amplifier. Mojab and Mazumder (2016) proposed an optical Darlington transistor for high-power applications. Weng etal. (2012) proposed broadband DA using heterojunction bipolar transistor for high-speed data communications. Various designs have been proposed for DA. Lee and Cressler (2005) proposed the design of ultra-wideband DA. Weng etal. (2010) proposed a design of DA for microwave broadband applications. Darlington pair topology is also used in medium PA for wireless and wireline data technology (Z. He etal., 2020). To obtain the large bandwidth and watt-level power output for satellite communication, Darlington power stage is used in two stages (Cai etal., 2020). It is also used in GaN HEMT Darlington PA for high efficiency, large dynamic range and low distortion characteristics (Kitamura etal., 2018).