@article {Owen:1958:0003-7028:129,
	author = "Owen, Louis E.",
	title = "Arc-Spark Source Unit Changes",
	journal = "Applied Spectroscopy",
	volume = "12",
	number = "4",
	year = "1958",
	abstract = "In commercial d.c. arc power supplies using a motor-driven variable reactor; it is not possible to predict accurately the excitation current before the arc is started. To permit pre-arc setting of the current, a circuit (Figure 1) is in use which temporarily shorts the d.c. so that its level can be adjusted. The circuit requires two relays which are energized by a single switch. One relay pulls in fast and drops out slowly; the other pulls in slowly and drops out fast. The fast-in, slow-out relay R<SUB>1</SUB> is used to disconnect the normal output and timing circuits and to short the d.c. output internally. The slow-in, fast-out relay R<SUB>2</SUB> connects the primary input power to the rectifier circuit. The relays can be time-delay types using hydraulic or pneumatic principles for delay, or they can be fed through RC networks as shown in Figure 1.",
	pages = "129-130",
	url = "http://www.ingentaconnect.com/content/sas/sas/1958/00000012/00000004/art00008",
	doi = "doi:10.1366/000370258774615429"
}