SPECIAL FOCUS PAPER REMOTE LAB EXPERIMENTS IN ELECTRONICS FOR USE AND REUSE Remote Lab Experiments in Electronics for Use and Reuse http://dx.doi.org/10.3991/ijim.v9i2.4346 T. Zimmer, M. Billaud, M. Pic, D. Geoffroy University of Bordeaux, Talence, France Abstract—This paper presents a new approach for the use of an already existing remote lab in the field of electrical engi- neering education. About 70 experiments representing a wide domain of electronic functions are easily accessible and can be incorporated into an existing teaching environment by an easy copy/paste action of a dedicated URL. The corre- sponding database structure is explained and a typical re- sult is given to highlight the procedure to follow. Index Terms—Laboratory experiments, Remote labs, Reuse of remote labs, Engineering education I. INTRODUCTION In sciences education, experimental methods are crucial for understanding basic concepts students face during practical sessions. Moreover, experimental methods give students an opportunity to develop their perceptions and autonomy and, finally, to increase their interest in a given topic. In the electrical engineering (EE) curriculum, com- prehension of electrical functions realized through simple circuits is a key for successful achievement of educational goals. Physical realization of the function leads to non- idealities that must be quantified by electrical measure- ments [1]. Furthermore, limitations of the measurement condition and the measurement resolution have to be ana- lyzed [2]. A remote laboratory for characterizing electron- ic circuits has many advantages: it allows sharing high- quality instruments and full-custom circuits that cannot be duplicated in several labs for cost reasons. Net-based access allows the users to launch experiments and analyze the results any place as often as they want [3]. The remote laboratories’ usefulness, acceptance and learning results have already been proven [4] and consolidated studies are in progress [5]. Setting up a remote lab demands not only knowledge in electrical engineering, but also knowledge in computer science, making the whole procedure quite complex. Many remote labs already exist and are referenced (e.g., on the lab2go platform) [6] or can be available through remote lab networks [7]. The reuse of remote labs is not straightforward. From a pedagogical point of view, the associated learning content rarely fits with what is neces- sary for a given lecture; in addition, the “overhead” activi- ties such as enrollment in an existing remote lab, authenti- cation and reservation for their employment for a given time slot very often represent very often a serious obstacle for wide use/reuse of existing remote labs. In this paper we report a new approach for reusing re- mote labs. First, we present a library in which about 70 different experiments are listed and described. These ex- periments cover about 80% to 90% of the electronic func- tions that are commonly investigated during electrical engineering education up to the bachelor’s level. Next, we present the organization of the database where all infor- mation about these circuits can be found. Finally, we show how each professor/teacher/instructor can access these experiments by simply copying/pasting one single hyper- link and integrating this link inside his personal teaching material. Of course, the teaching material must be availa- ble online (e.g., using OER or an LMS such as Moodle). The paper is organized as follows: Section 2 gives an overview of the 70 experiments that can be freely used; Section 3 describes the database architecture illustrating the different experiments; Section 4 develops how a pro- fessor/teacher/instructor can integrate these remote exper- iments into his own learning environment by a simple copy/past operation; and finally, a conclusion is given in Section 5. II. AVAILABLE EXPERIMENTS The different electronic circuits that are usually exam- ined during electrical engineering education can be classi- fied into different categories: A. Passive Electronic Circuits In the easiest form, a passive circuit is only a dipole such as a resistor, a capacitor, or an inductor. Combining C and R components can form a passive low-pass or high- pass filter, and by adding an inductor, the three compo- nents can form a resonant circuit. All these different kinds of circuits are available for frequency domain measure- ment (e.g., Bode-diagram of a filter) as well as in the time domain thanks to the employment of a function generator and an oscilloscope. B. Diodes And Transistors Based Circuits Diodes and transistors form the foundation of any elec- tronic circuit. Their investigations in many configurations are available: a. Diode half wave rectifier b. Common emitter amplifier (in different configura- tions) c. Emitter follower d. Common base amplifier e. PNP-common emitter amplifier f. Push-Pull output stage g. The transistor as a switch Most of the circuits can be investigated in both time domain and frequency domain. iJIM ‒ Volume 9, Issue 2, 2015 13 SPECIAL FOCUS PAPER REMOTE LAB EXPERIMENTS IN ELECTRONICS FOR USE AND REUSE C. Emitter Coupled Pair Circuits The next class concerns the differential amplifier. For the realization of this function, different configurations are possible and can be examined: a. Differential amplifier with long tail current source b. Differential amplifier with active current source c. Differential amplifier with passive load d. Differential amplifier with active load To get the whole picture of the differential amplifier, it can be investigated in differential mode and in common mode. D. Op-Amp Based Circuits Operational amplifiers are basic building blocks for many electronic functions such as a. Comparator with Op-Amp (741), Slewrate b. Comparator with Op-Amp (TL081), Slewrate c. Op-Amp Amplifier in closed loop, input imped- ance investigation d. Active low pass filter e. Comparator (inverted) f. Comparator with a threshold g. Derivator h. Integrator i. Inverter, voltage gain=2 j. Inverter, voltage gain = 10 k. Voltage follower l. Non-Inverter m. Non-Inverter, voltage gain=10 n. Non-Inverter, voltage gain ~ 50 o. Non-Inverter, Output current limits investigation p. Op-Amp with positive feedback q. Schmitt-Trigger All of these circuits can be investigated through the re- mote lab. III. ARCHITECTURE OF THE DATABASE For the creation of the database, we used SQLite through the SQL language. Furthermore, thanks to the PHP language and the function jQuery from Javascript we generated a table that shows information about the circuits on different levels: The first level contains the basic information such as (see Fig.1): a. Reference: a reference code for identifying the ex- periment b. Title: a first indication about the experiment c. Details: detailed information about the experiment d. Component : list of the components used e. Liens : hypertext link for access to the experiment in a different learning environment through copy/paste The second level contains detailed information about each experiment; it can be accessed by clicking on the !- icon (see Fig.2): Figure 1. First level of information for the experiments Figure 2. Second level of information for the experiments a. Title b. Maximum settings for time-domain measurements c. Typical settings for time-domain measurements d. Maximum settings for frequency-domain meas- urements e. Typical settings for frequency-domain measure- ments f. A description in French g. A description in English h. A picture-icon The third level gives additional information for each experiment (see Fig.3): Image 1: the circuit diagram Image 2: a photograph of the module Image 3: a typical measurement result in time domain Image 4: a typical measurement result in frequency domain Furthermore, an administrator interface has been set up that permits users to change/add/delete all the information that is in the database on the fly. Figure 4 shows the inter- face dedicated to adding another experiment. 14 http://www.i-jim.org SPECIAL FOCUS PAPER REMOTE LAB EXPERIMENTS IN ELECTRONICS FOR USE AND REUSE Figure 3. Third level of information for the experiments Figure 4. User interface for administration of the data base IV. USING THE EXPERIMENTS This section describes how to incorporate a remote ex- periment into a given learning environment. In the first step, we assume the professor/teacher/ instructor has made his choice from among the different experiments he wants to use. Next he clicks on the hyperlink, called “liens,” seen in the first table (see Fig.1). When doing so, a win- dow pops up indicating the link that has to be copied and pasted into the teacher’s document (see Fig.5). Figure 5. Typical link to copy/paste The name “X” is different for each experiment and the user does not have to worry about it. Now, when the student works with the teacher’s learn- ing material and clicks on the link that has been incorpo- rated by the teacher into those learning documents, a win- dow opens asking the students to specify the stimuli (set- tings for the measurement instruments, such as voltage level, to apply the frequency, the wave form and so on). An example is shown in Fig.6. These data are then trans- ferred to our remote lab (www.real-lab.org), and the measurement is executed by applying the above stimuli. When the measurement is completed, the results are transferred to the student’s computer and are displayed. (An example is shown in Fig.7) Now the student can ex- ploit the measured data and respond to the teacher’s spe- cific questions. Figure 6. Measurement interface specifying the settings Figure 7. An example of measurement results V. CONCLUSION In this paper we presented a new approach about how to use an already existing remote lab in the field of electrical engineering education. Approximately 70 experiments describing a wide domain of electronic functions are easi- ly reachable and can be incorporated in any existing re- motely accessible teaching environment by a straightfor- ward copy/paste action. An overview of the 70 experi- ments has been given and the corresponding database structure has been explained. In a cookbook manner, the procedure about how a professor/teacher/instructor can simply incorporate a given experiment in his private teaching documents is explained. The main advantage compared to existing solutions is that in the proposed approach, the instructor/teacher/professor has maximum freedom in constructing his course and can easily enhance the course content by adding real lab modules, so the students will benefit from the real world applications. iJIM ‒ Volume 9, Issue 2, 2015 15 SPECIAL FOCUS PAPER REMOTE LAB EXPERIMENTS IN ELECTRONICS FOR USE AND REUSE REFERENCES [1] M Billaud, T Zimmer, D Geoffroy, Y Danto, H Effinger, W Seifert, J Martinez, F Gomez, “Real measures, virtual instru- ments,” Proceedings of the Fourth IEEE International Caracas Conference on Devices, Circuits and Systems, I023-1-I023-4, 2002 [2] T Zimmer, M Billaud, D Geoffroy, “Remote laboratory for elec- trical engineering education,” International Journal of Online En- gineering 2 (3), 2006 [3] N Lewis, M Billaud, D Geoffroy, P Cazenave, T Zimmer, “A distance measurement platform dedicated to electrical engineer- ing,” Learning Technologies, IEEE Transactions on 2 (4), 312- 319, 2009 http://dx.doi.org/10.1109/TLT.2009.45 [4] D Lang, C Mengelkamp, RS Jäger, D Geoffroy, M Billaud, T Zimmer, “Pedagogical evaluation of remote laboratories in eMerge project,” European Journal of Engineering Education 32 (1), 57-72 http://dx.doi.org/10.1080/03043790601055626 [5] T. Tsiatsos, S. Douka, T. Zimmer, D. Geoffroy, “Evaluation plan of a network of remote labs in the Maghrebian countries”, Confer- ence REV 2014, February 26-28, 2014, Porto, Portugal http://dx.doi.org/10.1109/REV.2014.6784255 [6] www.lab2go.net [7] T. Zimmer, D. Geoffroy, A. Pester, R. Oros, T. Tsiatsos, S. Dou- ka, “ eSience: Setting up a network of remote labs in the Maghre- bian countries” iCEER International Conference on Engineering Education and Research, Marrakesh, July 1st-5th, 2013, Morocco AUTHORS T. Zimmer is with the Department of Applied Physics and Measurement Engineering at the Institute of Technol- ogy at the University of Bordeaux. He received a M.Sc. in Physics from the University of Würzburg, Germany, in 1989 and a Ph.D. in Electronics from the University Bor- deaux 1, Talence, France, in 1992. From 1989 to 1990, he was with the Fraunhofer Institute, Erlangen, Germany. Since 1992, he has been with the IMS Institute, Talence, France. Since 2003, he has been a professor at the Univer- sity of Bordeaux. At the IMS lab, he is the leader of the research group “Nanoelectronics.” He is a cofounder of XMOD Technologies and a senior member of IEEE. He has published more than 200 peer-reviewed scientific articles, 1 book and contributed to 8 book-chapters. His education interests concern multimedia, open and distance learning and the implementation of ICT (information and communication technologies) in lab courses. In particular, he was the coordinator of 3 European projects dedicated to remote labs. M. Billaud is with the Computer Science Department at the Institute of Technology at the University of Bor- deaux, France. He received a PhD in Applied Mathemat- ics (computer science specialty) from the University of Bordeaux 1, France, in 1985. He joined the Institut Uni- versitaire de Technologie de l’Université Bordeaux 1, where he teaches mainly about operating systems, pro- gramming, and networks. His research interests include formal semantics, graph rewriting, and e-learning. He has been involved in various e-learning projects in Bordeaux since 2000. M. Pic was a third year student when doing this work at the Computer Science Department at the Institute of Technology at the University of Bordeaux, France. D. Geoffroy is with the Electrical Engineering Depart- ment at the University of Bordeaux, France. He received an MSc in Applied Physics from the University of Orsay, Paris, in 1980. He is currently an associate professor in the Department of Electrical and Electronic Engineering at the University of Bordeaux and is also the head of the Peda- gogical Lab Center of this department. His special inter- ests include multimedia, open and distance learning, and the implementation of information and communication technologies (ICT) in practical courses. This project has been funded with support from the European Commis- sion. This publication reflects the views of only the authors, and the Commission cannot be held responsible for any use which may be made of the information contained therein. Submitted, December, 19, 2014. Published as resubmitted by the authors on May, 16, 2015. 16 http://www.i-jim.org iJIM Vol. 9, No, 2, 2015 Remote Lab Experiments in Electronics for Use and Reuse