GB584106A - Improvements in vibrator circuit with primary circuit division - Google Patents

Abstract

584,106. Converting. PLESSEY CO., Ltd. Dec. 18, 1944, No. 25335. Convention date, Jan. 4. [Class 38 (ii)] A vibrator system comprises twin primary transformer windings 11, 12, a current source 10 connected to the midpoints of these windings, an electromagnetic vibrator 15, four contacts 21, 22 and 23, 24, two on each side of the vibrator reed 20, one contact being connected to each of the four ends of the primary windings. When the reed touches the upper contacts 21, 22, current impulses pass from source 10 through the upper halves of each primary winding 11, 12 and when it touches lower contacts 23, 24 current impulses are sent through the lower halves of the windings in the reverse direction so that A.C. is induced in the common transformer secondaryc 14. The vibrator 15 is energized when oontacts 21, 22 are broken by current passings through the upper halves of both primaries and de-energized when the vibrator coil is short-circuited by the making of contacts 21, 22. By the connection of the vibrator coil to the mid-point of a resistor 18 both contacts 21, 22 must be closed to completely de-energize the coil, so that both contacts participate equally in the driver coil action and their life is prolonged. In a modification, Fig. 2 (not shown), the same result is achieved by there being two vibrator windings instead of the centre tapped resistor 18, and two outputs are obtained by each transformer primary being coupled to,a separate secondary.