GB1517794A - Optical guidance systems for missiles - Google Patents

Abstract

1517794 Missile guidance systems BOFORS AB 28 Aug 1975 [28 Aug 1974 4 Dec 1974] 35613/75 Heading G3N The power of a light beam in an optical missile guidance system is controlled in such a way that the beam is of low power until firing and the power of the beam is increased during flight of the missile. As described, a laser diode (1), Fig. 1 (not shown) is controlled by a pulser (2) controlled in turn by a servodevice (3) which compares a signal from a photo-detector (5) in the beam and a reference signal Fig. 3, from a control circuit (4) shown in Fig. 2. Before firing, transistor 8 is kept on by a negative signal applied to its base, whereby transistors 9, 10 are on, off respectively and a voltage Po is transmitted from the junction of resistors 15, 16 to servodevice 21. Upon firing, a positive signal is applied to transistor 8 to switch it off; capacitor 20 begins to charge and so transistor 9 begins to turn off. The voltage between resistors 15, 16 rises as shown in Fig. 3 until at time t 1 transistor 10 turns on, causing the output to servo 21 to remain constant at Pm.