SU394920A1 - RELAXATION AUTOGENERATOR - Google Patents

Description

one

The invention relates to a pulse technique and can be used as a master oscillator, where it is required to obtain a clock pulse or rectangular oscillations of the "meydr" type.

Relaxation oscillators are known on two transistors with grounded emitters and with a feedback circuit between the collector of the second transistor and the base of the first, containing a quartz resonator.

However, the known oscillators are complex and do not have a soft self-excitation mode.

In order to simplify the circuit and maintain a soft self-excitation mode in the proposed relaxation oscillator, the collector of the first transistor is directly connected to the base of the second, while resistors are connected between the base and collector of each transistor, as well as collectors of the second transistor.

The drawing shows the principal electrical circuit of the proposed relaxation oscillator.

The oscillator contains transistors / and 2 with grounded emitters. Between the collector of the transistor 2 and the base of the transistor / there is a feedback circuit, which includes a crystal oscillator 3. The collector of the transistor / is directly connected to

The base of transistor 2. A resistor 4 is connected between the base of the transistor / and its collector, and the base and collector of transistor 2 are connected through a resistor 5. The collector of transistor 2 is connected to a power source through a resistor 6. The generator output is point 7.

The generator is well excited if, instead of the quartz resonator 3, the LC circuit or capacitor is turned on, and in the latter case the generator generates pulses with a high duty cycle, determined by the ratio of resistors 4 and 6.

In the proposed embodiment, the circuit uses fused transistors 1 and 2, which withstand a large (on the order of supply voltage) reverse voltage at the base-emitter junction. To use drift transistors (for the purpose of raising the frequency ceiling) with a low base voltage emitter, you must turn on the diode, as shown in the diagram (diode 8).

In this case, "square wave" oscillations are generated.

Subject invention

Relaxation oscillator on two

ranzistor with grounded emitters and

with feedback loop between the collector

The second transistor and the base of the first one, which contains the time setting element, for example, a quartz resonator, characterized in that, in order to simplify the circuit and maintain a soft self-excitation mode, the collector of the first transistor is directly connected to the base of the second transistor between this base and the collector of each the transistor as well as the collector of the second transistor and the power source include resistors.

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