GB1284517A - Timing light control circuit - Google Patents

Abstract

1284517 Transistor pulse circuits INTERNATIONAL BUSINESS MACHINES CORP 19 April 1971 [30 April 1970] 26434/71 Heading H3T [Also in Division G1] Pulse shapes.-A pulse train from the breaker contacts 10 (Fig. 3) of an I.C. engine is fed through a unit 24, comprising a filter 100 (Fig. 5) and a multivibrator having a normally blocked transistor 95 which is opened by each input pulse to produce a negative output pulse 105 on line 92. The output pulse duration is determined by the time taken for capacitor 104 to charge to a potential which opens transistor 108 and blocks transistor 95, and is made to coincide with the input pulse duration. Delay circuits.-A potential on line 96 (Fig. 5) controls the extension of each pulse 60 fed to a monostable multivibrator comprising transistors 41, 45. The input potential charges capacitor 31. Each pulse 60 blocks diode 34, opens transistor 41 and blocks transistor 45, to start the output pulse 61. Capacitor 31 discharges through transistor 50 at a rate determined by manually adjustable bias potential applied on line 26. When the capacitor potential applied is sufficiently low, diode 144 conducts and opens transistor 45 to end the output pulse 61. The leading edge of pulse 61 on lead 68 (Fig. 4) opens transistor 71 to produce a negative pulse at 84 which is blocked by diode 75. The trailing edge blocks transistor 71 to produce a positive pulse which is amplified at 78, 80 to form output pulse 62.