| 摘要 |
FIELD: pulse devices, pulse generators using flip-flops. SUBSTANCE: device has RS-flip-flop, which is designed from CMOS-transistors, two capacitors, two resistors, diode and single-junction transistor. R and S inputs of flip-flop are connected to zero line through capacitors. They are also connected to its direct and inverse outputs through resistors. Diode is connected in parallel to one resistor, so that its anode is connected to input of flip-flop and its cathode is connected to output of flip-flop. Emitter of single-junction transistor is connected to R-input of flip-flop, first base is connected to zero line, second base is connected to direct output of flip-flop. When voltage is applied to circuit, two cases are possible, first: voltage at one of flip-flop inputs reaches threshold quicker than at another one; second: voltage at both inputs simultaneously exceeds threshold. In first case, circuit will operate in generation mode. In second case, if surge at input circuits or power supply lines leads to simultaneous threshold level at both inputs of flip-flop, high logical level signal is set at both outputs of flip-flop. In this case, second base-emitter junction of transistor is closed, this leads to quick discharge of corresponding capacitor through said junction. This results in voltage drop at R-input of flip-flop, so circuit continues its operations in generation mode. When circuit operates in generation mode, transistor does not influence characteristics of generated pulse sequence. EFFECT: increased stability to surges. |
