| 摘要 |
<p>The viewer includes a transparency positioned between a 150W bulb (1) and a sheet of unpolished glass. The 150 W bulb is connected in circuit with an ammeter, and voltmeter to measure the power used. A potentiometer controls the voltage applied so as to vary the power between 75 and 150 W. Power is derived from the mains, and there is a red indicator to show when the power is switched on. In parallel with the main bulb there is a low power bulb, (2). The viewer may be used for a wide variety of purposes, according to the type of image displayed. It may be used for educational pruposes, or by displaying, for example a flower, it may be used in hypnosis or yoga. With alternative images it may be used to simulate military activities in training.</p> |
